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https://github.com/BelfrySCAD/BOSL2.git
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1099 lines
39 KiB
OpenSCAD
1099 lines
39 KiB
OpenSCAD
//////////////////////////////////////////////////////////////////////
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// LibFile: arrays.scad
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// List and Array manipulation functions.
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// To use, add the following lines to the beginning of your file:
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// ```
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// use <BOSL2/std.scad>
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// ```
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//////////////////////////////////////////////////////////////////////
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// Section: Terminology
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// - **List**: An ordered collection of zero or more items. ie: `["a", "b", "c"]`
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// - **Vector**: A list of numbers. ie: `[4, 5, 6]`
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// - **Array**: A nested list of lists, or list of lists of lists, or deeper. ie: `[[2,3], [4,5], [6,7]]`
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// - **Dimension**: The depth of nesting of lists in an array. A List is 1D. A list of lists is 2D. etc.
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// Section: List Query Operations
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// Function: select()
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// Description:
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// Returns a portion of a list, wrapping around past the beginning, if end<start.
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// The first item is index 0. Negative indexes are counted back from the end.
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// The last item is -1. If only the `start` index is given, returns just the value
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// at that position.
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// Usage:
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// select(list,start)
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// select(list,start,end)
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// Arguments:
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// list = The list to get the portion of.
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// start = The index of the first item.
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// end = The index of the last item.
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// Example:
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// l = [3,4,5,6,7,8,9];
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// select(l, 5, 6); // Returns [8,9]
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// select(l, 5, 8); // Returns [8,9,3,4]
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// select(l, 5, 2); // Returns [8,9,3,4,5]
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// select(l, -3, -1); // Returns [7,8,9]
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// select(l, 3, 3); // Returns [6]
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// select(l, 4); // Returns 7
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// select(l, -2); // Returns 8
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// select(l, [1:3]); // Returns [4,5,6]
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// select(l, [1,3]); // Returns [4,6]
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function select(list, start, end=undef) =
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let(l=len(list))
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end==undef? (
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is_num(start)?
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let(s=(start%l+l)%l) list[s] :
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[for (i=start) list[(i%l+l)%l]]
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) : (
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let(s=(start%l+l)%l, e=(end%l+l)%l)
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(s<=e)?
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[for (i = [s:1:e]) list[i]] :
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concat([for (i = [s:1:l-1]) list[i]], [for (i = [0:1:e]) list[i]])
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);
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// Function: slice()
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// Description:
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// Returns a slice of a list. The first item is index 0.
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// Negative indexes are counted back from the end. The last item is -1.
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// Arguments:
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// arr = The array/list to get the slice of.
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// st = The index of the first item to return.
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// end = The index after the last item to return, unless negative, in which case the last item to return.
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// Example:
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// slice([3,4,5,6,7,8,9], 3, 5); // Returns [6,7]
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// slice([3,4,5,6,7,8,9], 2, -1); // Returns [5,6,7,8,9]
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// slice([3,4,5,6,7,8,9], 1, 1); // Returns []
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// slice([3,4,5,6,7,8,9], 6, -1); // Returns [9]
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// slice([3,4,5,6,7,8,9], 2, -2); // Returns [5,6,7,8]
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function slice(arr,st,end) = let(
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s=st<0?(len(arr)+st):st,
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e=end<0?(len(arr)+end+1):end
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) [for (i=[s:1:e-1]) if (e>s) arr[i]];
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// Function: in_list()
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// Description: Returns true if value `x` is in list `l`.
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// Arguments:
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// x = The value to search for.
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// l = The list to search.
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// idx = If given, searches the given subindexes for matches for `x`.
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// Example:
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// in_list("bar", ["foo", "bar", "baz"]); // Returns true.
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// in_list("bee", ["foo", "bar", "baz"]); // Returns false.
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// in_list("bar", [[2,"foo"], [4,"bar"], [3,"baz"]], idx=1); // Returns true.
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function in_list(x,l,idx=undef) = search([x], l, num_returns_per_match=1, index_col_num=idx) != [[]];
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// Function: min_index()
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// Usage:
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// min_index(vals,[all]);
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// Description:
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// Returns the index of the first occurrence of the minimum value in the given list.
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// If `all` is true then returns a list of all indices where the minimum value occurs.
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// Arguments:
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// vals = vector of values
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// all = set to true to return indices of all occurences of the minimum. Default: false
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// Example:
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// min_index([5,3,9,6,2,7,8,2,1]); // Returns: 4
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// min_index([5,3,9,6,2,7,8,2,1],all=true); // Returns: [4,7]
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function min_index(vals, all=false) =
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all ? search(min(vals),vals,0) : search(min(vals), vals)[0];
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// Function: max_index()
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// Usage:
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// max_index(vals,[all]);
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// Description:
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// Returns the index of the first occurrence of the maximum value in the given list.
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// If `all` is true then returns a list of all indices where the maximum value occurs.
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// Arguments:
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// vals = vector of values
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// all = set to true to return indices of all occurences of the maximum. Default: false
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// Example:
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// max_index([5,3,9,6,2,7,8,9,1]); // Returns: 2
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// max_index([5,3,9,6,2,7,8,9,1],all=true); // Returns: [2,7]
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function max_index(vals, all=false) =
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all ? search(max(vals),vals,0) : search(max(vals), vals)[0];
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// Function: list_increasing()
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// Usage:
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// list_increasing(list)
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// Description:
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// Returns true if the list is (non-strictly) increasing
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// Example:
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// list_increasing([1,2,3,4]); // Returns: true
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// list_increasing([1,3,2,4]); // Returns: false
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// list_increasing([4,3,2,1]); // Returns: false
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function list_increasing(list) =
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assert(is_list(list)||is_string(list))
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len([for (p=pair(list)) if(p.x>p.y) true])==0;
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// Function: list_decreasing()
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// Usage:
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// list_decreasing(list)
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// Description:
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// Returns true if the list is (non-strictly) decreasing
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// Example:
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// list_decreasing([1,2,3,4]); // Returns: false
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// list_decreasing([4,2,3,1]); // Returns: false
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// list_decreasing([4,3,2,1]); // Returns: true
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function list_decreasing(list) =
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assert(is_list(list)||is_string(list))
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len([for (p=pair(list)) if(p.x<p.y) true])==0;
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// Section: Basic List Generation
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// Function: repeat()
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// Usage:
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// repeat(val, n)
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// Description:
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// Generates a list or array of `n` copies of the given `list`.
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// If the count `n` is given as a list of counts, then this creates a
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// multi-dimensional array, filled with `val`.
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// Arguments:
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// val = The value to repeat to make the list or array.
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// n = The number of copies to make of `val`.
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// Example:
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// repeat(1, 4); // Returns [1,1,1,1]
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// repeat(8, [2,3]); // Returns [[8,8,8], [8,8,8]]
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// repeat(0, [2,2,3]); // Returns [[[0,0,0],[0,0,0]], [[0,0,0],[0,0,0]]]
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// repeat([1,2,3],3); // Returns [[1,2,3], [1,2,3], [1,2,3]]
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function repeat(val, n, i=0) =
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is_num(n)? [for(j=[1:1:n]) val] :
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(i>=len(n))? val :
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[for (j=[1:1:n[i]]) repeat(val, n, i+1)];
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// Function: list_range()
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// Usage:
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// list_range(n, [s], [e])
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// list_range(n, [s], [step])
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// list_range(e, [step])
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// list_range(s, e, [step])
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// Description:
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// Returns a list, counting up from starting value `s`, by `step` increments,
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// until either `n` values are in the list, or it reaches the end value `e`.
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// If both `n` and `e` are given, returns `n` values evenly spread fron `s`
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// to `e`, and `step` is ignored.
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// Arguments:
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// n = Desired number of values in returned list, if given.
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// s = Starting value. Default: 0
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// e = Ending value to stop at, if given.
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// step = Amount to increment each value. Default: 1
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// Example:
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// list_range(4); // Returns [0,1,2,3]
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// list_range(n=4, step=2); // Returns [0,2,4,6]
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// list_range(n=4, s=3, step=3); // Returns [3,6,9,12]
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// list_range(n=5, s=0, e=10); // Returns [0, 2.5, 5, 7.5, 10]
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// list_range(e=3); // Returns [0,1,2,3]
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// list_range(e=6, step=2); // Returns [0,2,4,6]
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// list_range(s=3, e=5); // Returns [3,4,5]
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// list_range(s=3, e=8, step=2); // Returns [3,5,7]
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// list_range(s=4, e=8, step=2); // Returns [4,6,8]
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// list_range(n=4, s=[3,4], step=[2,3]); // Returns [[3,4], [5,7], [7,10], [9,13]]
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function list_range(n=undef, s=0, e=undef, step=undef) =
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(n!=undef && e!=undef)? (
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assert(is_undef(n) || is_undef(e) || is_undef(step), "At most 2 of n, e, and step can be given.")
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[for (i=[0:1:n-1]) s+(e-s)*i/(n-1)]
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) : let(step = default(step,1))
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(n!=undef)? [for (i=[0:1:n-1]) let(v=s+step*i) v] :
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(e!=undef)? [for (v=[s:step:e]) v] :
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assert(e!=undef||n!=undef, "Must supply one of `n` or `e`.");
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// Section: List Manipulation
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// Function: reverse()
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// Description: Reverses a list/array.
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// Arguments:
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// list = The list to reverse.
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// Example:
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// reverse([3,4,5,6]); // Returns [6,5,4,3]
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function reverse(list) =
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assert(is_list(list)||is_string(list))
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[ for (i = [len(list)-1 : -1 : 0]) list[i] ];
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// Function: list_rotate()
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// Usage:
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// rlist = list_rotate(list,n);
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// Description:
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// Rotates the contents of a list by `n` positions left.
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// If `n` is negative, then the rotation is `abs(n)` positions to the right.
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// Arguments:
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// list = The list to rotate.
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// n = The number of positions to rotate by. If negative, rotated to the right. Positive rotates to the left. Default: 1
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// Example:
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// l1 = list_rotate([1,2,3,4,5],-2); // Returns: [4,5,1,2,3]
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// l2 = list_rotate([1,2,3,4,5],-1); // Returns: [5,1,2,3,4]
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// l3 = list_rotate([1,2,3,4,5],0); // Returns: [1,2,3,4,5]
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// l4 = list_rotate([1,2,3,4,5],1); // Returns: [2,3,4,5,1]
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// l5 = list_rotate([1,2,3,4,5],2); // Returns: [3,4,5,1,2]
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// l6 = list_rotate([1,2,3,4,5],3); // Returns: [4,5,1,2,3]
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// l7 = list_rotate([1,2,3,4,5],4); // Returns: [5,1,2,3,4]
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// l8 = list_rotate([1,2,3,4,5],5); // Returns: [1,2,3,4,5]
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// l9 = list_rotate([1,2,3,4,5],6); // Returns: [2,3,4,5,1]
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function list_rotate(list,n=1) =
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assert(is_list(list)||is_string(list))
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assert(is_num(n))
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select(list,n,n+len(list)-1);
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// Function: deduplicate()
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// Usage:
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// deduplicate(list);
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// Description:
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// Removes consecutive duplicate items in a list.
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// This is different from `unique()` in that the list is *not* sorted.
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// Arguments:
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// list = The list to deduplicate.
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// closed = If true, drops trailing items if they match the first list item.
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// eps = The maximum difference to allow between numbers or vectors.
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// Examples:
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// deduplicate([8,3,4,4,4,8,2,3,3,8,8]); // Returns: [8,3,4,8,2,3,8]
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// deduplicate(closed=true, [8,3,4,4,4,8,2,3,3,8,8]); // Returns: [8,3,4,8,2,3]
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// deduplicate("Hello"); // Returns: ["H","e","l","o"]
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// deduplicate([[3,4],[7,2],[7,1.99],[1,4]],eps=0.1); // Returns: [[3,4],[7,2],[1,4]]
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function deduplicate(list, closed=false, eps=EPSILON) =
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assert(is_list(list)||is_string(list))
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let(
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l = len(list),
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end = l-(closed?0:1)
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) (is_num(list[0]) || is_vector(list[0]))?
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[for (i=[0:1:l-1]) if (i==end || !approx(list[i], list[(i+1)%l], eps)) list[i]] :
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[for (i=[0:1:l-1]) if (i==end || list[i] != list[(i+1)%l]) list[i]];
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// Function: repeat_entries()
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// Usage:
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// newlist = repeat_entries(list, N)
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// Description:
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// Takes a list as input and duplicates some of its entries to produce a list
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// with length `N`. If the requested `N` is not a multiple of the list length then
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// the entries will be duplicated as uniformly as possible. You can also set `N` to a vector,
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// in which case len(N) must equal len(list) and the output repeats the ith entry N[i] times.
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// In either case, the result will be a list of length `N`. The `exact` option requires
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// that the final length is exactly as requested. If you set it to `false` then the
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// algorithm will favor uniformity and the output list may have a different number of
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// entries due to rounding.
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//
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// When applied to a path the output path is the same geometrical shape but has some vertices
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// repeated. This can be useful when you need to align paths with a different number of points.
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// (See also subdivide_path for a different way to do that.)
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// Arguments:
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// list = list whose entries will be repeated
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// N = scalar total number of points desired or vector requesting N[i] copies of vertex i.
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// exact = if true return exactly the requested number of points, possibly sacrificing uniformity. If false, return uniform points that may not match the number of points requested. Default: True
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// Examples:
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// list = [0,1,2,3];
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// echo(repeat_entries(list, 6)); // Ouputs [0,0,1,2,2,3]
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// echo(repeat_entries(list, 6, exact=false)); // Ouputs [0,0,1,1,2,2,3,3]
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// echo(repeat_entries(list, [1,1,2,1], exact=false)); // Ouputs [0,1,2,2,3]
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function repeat_entries(list, N, exact = true) =
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assert(is_list(list))
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assert((is_num(N) && N>0) || is_vector(N),"Parameter N to repeat_entries must be postive number or vector")
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let(
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length = len(list),
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reps_guess = is_list(N)?
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assert(len(N)==len(list), "Vector parameter N to repeat_entries has the wrong length")
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N : repeat(N/length,length),
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reps = exact? _sum_preserving_round(reps_guess) :
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[for (val=reps_guess) round(val)]
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)
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[for(i=[0:length-1]) each repeat(list[i],reps[i])];
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// Function: list_set()
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// Usage:
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// list_set(list, indices, values, [dflt], [minlen])
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// Description:
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// Takes the input list and returns a new list such that `list[indices[i]] = values[i]` for all of
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// the (index,value) pairs supplied. If you supply `indices` that are beyond the length of the list
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// then the list is extended and filled in with the `dflt` value. If you set `minlen` then the list is
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// lengthed, if necessary, by padding with `dflt` to that length. The `indices` list can be in any
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// order but run time will be (much) faster for long lists if it is already sorted. Reptitions are
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// not allowed. If `indices` is given as a non-list scalar, then that index of the given `list` will
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// be set to the value of `values`.
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// Arguments:
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// list = List to set items in. Default: []
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// indices = List of indices into `list` to set.
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// values = List of values to set.
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// dflt = Default value to store in sparse skipped indices.
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// minlen = Minimum length to expand list to.
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// Examples:
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// list_set([2,3,4,5], 2, 21); // Returns: [2,3,21,5]
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// list_set([2,3,4,5], [1,3], [81,47]); // Returns: [2,81,4,47]
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function list_set(list=[],indices,values,dflt=0,minlen=0) =
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assert(is_list(list)||is_string(list))
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!is_list(indices)? (
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(is_num(indices) && indices<len(list))? [for (i=idx(list)) i==indices? values : list[i]] :
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list_set(list,[indices],[values],dflt)
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) :
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assert(len(indices)==len(values),"Index list and value list must have the same length")
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let(
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sortind = list_increasing(indices) ? list_range(len(indices)) : sortidx(indices),
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lastind = len(indices)==0 ? -1 : indices[select(sortind,-1)]
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)
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concat(
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[for(j=[0:1:indices[sortind[0]]-1]) j>=len(list) ? dflt : list[j]],
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[values[sortind[0]]],
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[for(i=[1:1:len(sortind)-1]) each
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assert(indices[sortind[i]]!=indices[sortind[i-1]],"Repeated index")
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concat(
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[for(j=[1+indices[sortind[i-1]]:1:indices[sortind[i]]-1]) j>=len(list) ? dflt : list[j]],
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[values[sortind[i]]]
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)
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],
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slice(list,1+lastind, len(list)),
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repeat(dflt, minlen-lastind-1)
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);
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// Function: list_insert()
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// Usage:
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// list_insert(list, pos, elements);
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// Description:
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// Insert `elements` into `list` before position `pos`.
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// Example:
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// list_insert([3,6,9,12],1,5); // Returns [3,5,6,9,12]
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// list_insert([3,6,9,12],[1,3],[5,11]); // Returns [3,5,6,9,11,12]
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function list_insert(list, pos, elements, _i=0) =
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assert(is_list(list)||is_string(list))
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is_list(pos)? (
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assert(len(pos)==len(elements))
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let(
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idxs = sortidx(pos),
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lastidx = pos[idxs[len(idxs)-1]]
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)
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concat(
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[
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|
for(i=idx(idxs)) each concat(
|
|
assert(pos[idxs[i]]<=len(list), "Indices in pos must be <= len(list)")
|
|
[for (j=[(i==0?0:pos[idxs[i-1]]):1:pos[idxs[i]]-1]) list[j]],
|
|
[elements[idxs[i]]]
|
|
)
|
|
],
|
|
[for (j=[lastidx:1:len(list)-1]) list[j]]
|
|
)
|
|
) : (
|
|
assert(pos<=len(list), "Indices in pos must be <= len(list)")
|
|
concat(
|
|
slice(list,0,pos),
|
|
elements,
|
|
(pos<len(list)? slice(list,pos,-1) : [])
|
|
)
|
|
);
|
|
|
|
|
|
// Function: list_remove()
|
|
// Usage:
|
|
// list_remove(list, elements)
|
|
// Description:
|
|
// Remove all items from `list` whose indexes are in `elements`.
|
|
// Arguments:
|
|
// list = The list to remove items from.
|
|
// elements = The list of indexes of items to remove.
|
|
// Example:
|
|
// list_insert([3,6,9,12],1); // Returns: [3,9,12]
|
|
// list_insert([3,6,9,12],[1,3]); // Returns: [3,9]
|
|
function list_remove(list, elements) =
|
|
assert(is_list(list)||is_string(list))
|
|
!is_list(elements) ? list_remove(list,[elements]) :
|
|
len(elements)==0 ? list :
|
|
let(
|
|
sortind = list_increasing(elements) ? list_range(len(elements)) : sortidx(elements),
|
|
lastind = elements[select(sortind,-1)]
|
|
)
|
|
assert(lastind<len(list),"Element index beyond list end")
|
|
concat(slice(list, 0, elements[sortind[0]]),
|
|
[for(i=[1:1:len(sortind)-1]) each slice(list,1+elements[sortind[i-1]], elements[sortind[i]])],
|
|
slice(list,1+lastind, len(list))
|
|
);
|
|
|
|
|
|
// Function: list_remove_values()
|
|
// Usage:
|
|
// list_remove_values(list,values,all=false) =
|
|
// Description:
|
|
// Removes the first, or all instances of the given `values` from the `list`.
|
|
// Returns the modified list.
|
|
// Arguments:
|
|
// list = The list to modify.
|
|
// values = The values to remove from the list.
|
|
// all = If true, remove all instances of the value `value` from the list `list`. If false, remove only the first. Default: false
|
|
// Example:
|
|
// animals = ["bat", "cat", "rat", "dog", "bat", "rat"];
|
|
// animals2 = list_remove_values(animals, "rat"); // Returns: ["bat","cat","dog","bat","rat"]
|
|
// nonflying = list_remove_values(animals, "bat", all=true); // Returns: ["cat","rat","dog","rat"]
|
|
// animals3 = list_remove_values(animals, ["bat","rat"]); // Returns: ["cat","dog","bat","rat"]
|
|
// domestic = list_remove_values(animals, ["bat","rat"], all=true); // Returns: ["cat","dog"]
|
|
// animals4 = list_remove_values(animals, ["tucan","rat"], all=true); // Returns: ["bat","cat","dog","bat"]
|
|
function list_remove_values(list,values=[],all=false) =
|
|
assert(is_list(list)||is_string(list))
|
|
!is_list(values)? list_remove_values(list, values=[values], all=all) :
|
|
let(
|
|
idxs = all? flatten(search(values,list,0)) : search(values,list,1),
|
|
uidxs = unique(idxs)
|
|
) list_remove(list,uidxs);
|
|
|
|
|
|
// Function: bselect()
|
|
// Usage:
|
|
// bselect(array,index);
|
|
// Description:
|
|
// Returns the items in `array` whose matching element in `index` is true.
|
|
// Arguments:
|
|
// array = Initial list to extract items from.
|
|
// index = List of booleans.
|
|
// Example:
|
|
// bselect([3,4,5,6,7], [false,true,true,false,true]); // Returns: [4,5,7]
|
|
function bselect(array,index) =
|
|
assert(is_list(array)||is_string(array))
|
|
assert(is_list(index))
|
|
[for(i=[0:len(array)-1]) if (index[i]) array[i]];
|
|
|
|
|
|
// Function: list_bset()
|
|
// Usage:
|
|
// list_bset(indexset, valuelist,[dflt])
|
|
// Description:
|
|
// Opposite of `bselect()`. Returns a list the same length as `indexlist`, where each item will
|
|
// either be 0 if the corresponding item in `indexset` is false, or the next sequential value
|
|
// from `valuelist` if true. The number of `true` values in `indexset` must be equal to the length
|
|
// of `valuelist`.
|
|
// Arguments:
|
|
// indexset = A list of boolean values.
|
|
// valuelist = The list of values to set into the returned list.
|
|
// dflt = Default value to store when the indexset item is false.
|
|
// Example:
|
|
// list_bset([false,true,false,true,false], [3,4]); // Returns: [0,3,0,4,0]
|
|
// list_bset([false,true,false,true,false], [3,4],dflt=1); // Returns: [1,3,1,4,1]
|
|
function list_bset(indexset, valuelist, dflt=0) =
|
|
assert(is_list(indexset))
|
|
assert(is_list(valuelist))
|
|
let(
|
|
trueind = search([true], indexset,0)[0]
|
|
) concat(
|
|
list_set([],trueind, valuelist, dflt=dflt), // Fill in all of the values
|
|
repeat(dflt,len(indexset)-max(trueind)-1) // Add trailing values so length matches indexset
|
|
);
|
|
|
|
|
|
|
|
// Section: List Length Manipulation
|
|
|
|
// Function: list_shortest()
|
|
// Description:
|
|
// Returns the length of the shortest sublist in a list of lists.
|
|
// Arguments:
|
|
// vecs = A list of lists.
|
|
function list_shortest(vecs) =
|
|
assert(is_list(vecs)||is_string(list))
|
|
min([for (v = vecs) len(v)]);
|
|
|
|
|
|
// Function: list_longest()
|
|
// Description:
|
|
// Returns the length of the longest sublist in a list of lists.
|
|
// Arguments:
|
|
// vecs = A list of lists.
|
|
function list_longest(vecs) =
|
|
assert(is_list(vecs)||is_string(list))
|
|
max([for (v = vecs) len(v)]);
|
|
|
|
|
|
// Function: list_pad()
|
|
// Description:
|
|
// If the list `v` is shorter than `minlen` length, pad it to length with the value given in `fill`.
|
|
// Arguments:
|
|
// v = A list.
|
|
// minlen = The minimum length to pad the list to.
|
|
// fill = The value to pad the list with.
|
|
function list_pad(v, minlen, fill=undef) =
|
|
assert(is_list(v)||is_string(list))
|
|
concat(v,repeat(fill,minlen-len(v)));
|
|
|
|
|
|
// Function: list_trim()
|
|
// Description:
|
|
// If the list `v` is longer than `maxlen` length, truncates it to be `maxlen` items long.
|
|
// Arguments:
|
|
// v = A list.
|
|
// minlen = The minimum length to pad the list to.
|
|
function list_trim(v, maxlen) =
|
|
assert(is_list(v)||is_string(list))
|
|
[for (i=[0:1:min(len(v),maxlen)-1]) v[i]];
|
|
|
|
|
|
// Function: list_fit()
|
|
// Description:
|
|
// If the list `v` is longer than `length` items long, truncates it to be exactly `length` items long.
|
|
// If the list `v` is shorter than `length` items long, pad it to length with the value given in `fill`.
|
|
// Arguments:
|
|
// v = A list.
|
|
// minlen = The minimum length to pad the list to.
|
|
// fill = The value to pad the list with.
|
|
function list_fit(v, length, fill) =
|
|
assert(is_list(v)||is_string(list))
|
|
let(l=len(v)) (l==length)? v : (l>length)? list_trim(v,length) : list_pad(v,length,fill);
|
|
|
|
|
|
|
|
// Section: List Shuffling and Sorting
|
|
|
|
// Function: shuffle()
|
|
// Description:
|
|
// Shuffles the input list into random order.
|
|
function shuffle(list) =
|
|
assert(is_list(list)||is_string(list))
|
|
len(list)<=1 ? list :
|
|
let (
|
|
rval = rands(0,1,len(list)),
|
|
left = [for (i=[0:len(list)-1]) if (rval[i]< 0.5) list[i]],
|
|
right = [for (i=[0:len(list)-1]) if (rval[i]>=0.5) list[i]]
|
|
) concat(shuffle(left), shuffle(right));
|
|
|
|
|
|
// Sort a vector of scalar values
|
|
function _sort_scalars(arr) =
|
|
len(arr)<=1 ? arr : let(
|
|
pivot = arr[floor(len(arr)/2)],
|
|
lesser = [ for (y = arr) if (y < pivot) y ],
|
|
equal = [ for (y = arr) if (y == pivot) y ],
|
|
greater = [ for (y = arr) if (y > pivot) y ]
|
|
) concat( _sort_scalars(lesser), equal, _sort_scalars(greater) );
|
|
|
|
|
|
// Sort a vector of vectors based on the first entry only of each vector
|
|
function _sort_vectors1(arr) =
|
|
len(arr)<=1 ? arr :
|
|
!(len(arr)>0) ? [] : let(
|
|
pivot = arr[floor(len(arr)/2)],
|
|
lesser = [ for (y = arr) if (y[0] < pivot[0]) y ],
|
|
equal = [ for (y = arr) if (y[0] == pivot[0]) y ],
|
|
greater = [ for (y = arr) if (y[0] > pivot[0]) y ]
|
|
) concat( _sort_vectors1(lesser), equal, _sort_vectors1(greater) );
|
|
|
|
|
|
// Sort a vector of vectors based on the first two entries of each vector
|
|
// Lexicographic order, remaining entries of vector ignored
|
|
function _sort_vectors2(arr) =
|
|
len(arr)<=1 ? arr :
|
|
!(len(arr)>0) ? [] : let(
|
|
pivot = arr[floor(len(arr)/2)],
|
|
lesser = [ for (y = arr) if (y[0] < pivot[0] || (y[0]==pivot[0] && y[1]<pivot[1])) y ],
|
|
equal = [ for (y = arr) if (y[0] == pivot[0] && y[1]==pivot[1]) y ],
|
|
greater = [ for (y = arr) if (y[0] > pivot[0] || (y[0]==pivot[0] && y[1]>pivot[1])) y ]
|
|
) concat( _sort_vectors2(lesser), equal, _sort_vectors2(greater) );
|
|
|
|
// Sort a vector of vectors based on the first three entries of each vector
|
|
// Lexicographic order, remaining entries of vector ignored
|
|
function _sort_vectors3(arr) =
|
|
len(arr)<=1 ? arr : let(
|
|
pivot = arr[floor(len(arr)/2)],
|
|
lesser = [
|
|
for (y = arr) if (
|
|
y[0] < pivot[0] || (
|
|
y[0]==pivot[0] && (
|
|
y[1]<pivot[1] || (
|
|
y[1]==pivot[1] &&
|
|
y[2]<pivot[2]
|
|
)
|
|
)
|
|
)
|
|
) y
|
|
],
|
|
equal = [
|
|
for (y = arr) if (
|
|
y[0] == pivot[0] && y[1]== pivot[1] && y[2]==pivot[2]
|
|
) y
|
|
],
|
|
greater = [
|
|
for (y = arr) if (
|
|
y[0] > pivot[0] || (
|
|
y[0]==pivot[0] && (
|
|
y[1]>pivot[1] || (
|
|
y[1]==pivot[1] &&
|
|
y[2]>pivot[2]
|
|
)
|
|
)
|
|
)
|
|
) y
|
|
]
|
|
) concat( _sort_vectors3(lesser), equal, _sort_vectors3(greater) );
|
|
|
|
|
|
// Sort a vector of vectors based on the first four entries of each vector
|
|
// Lexicographic order, remaining entries of vector ignored
|
|
function _sort_vectors4(arr) =
|
|
len(arr)<=1 ? arr : let(
|
|
pivot = arr[floor(len(arr)/2)],
|
|
lesser = [
|
|
for (y = arr) if (
|
|
y[0] < pivot[0] || (
|
|
y[0]==pivot[0] && (
|
|
y[1]<pivot[1] || (
|
|
y[1]==pivot[1] && (
|
|
y[2]<pivot[2] || (
|
|
y[2]==pivot[2] &&
|
|
y[3]<pivot[3]
|
|
)
|
|
)
|
|
)
|
|
)
|
|
)
|
|
) y
|
|
],
|
|
equal = [
|
|
for (y = arr) if (
|
|
y[0] == pivot[0] &&
|
|
y[1] == pivot[1] &&
|
|
y[2] == pivot[2] &&
|
|
y[3] == pivot[3]
|
|
) y
|
|
],
|
|
greater = [
|
|
for (y = arr) if (
|
|
y[0] > pivot[0] || (
|
|
y[0]==pivot[0] && (
|
|
y[1]>pivot[1] || (
|
|
y[1]==pivot[1] && (
|
|
y[2]>pivot[2] || (
|
|
y[2]==pivot[2] &&
|
|
y[3]>pivot[3]
|
|
)
|
|
)
|
|
)
|
|
)
|
|
)
|
|
) y
|
|
]
|
|
) concat( _sort_vectors4(lesser), equal, _sort_vectors4(greater) );
|
|
|
|
|
|
function _sort_general(arr, idx=undef) =
|
|
(len(arr)<=1) ? arr :
|
|
let(
|
|
pivot = arr[floor(len(arr)/2)],
|
|
pivotval = idx==undef? pivot : [for (i=idx) pivot[i]],
|
|
compare = [
|
|
for (entry = arr) let(
|
|
val = idx==undef? entry : [for (i=idx) entry[i]],
|
|
cmp = compare_vals(val, pivotval)
|
|
) cmp
|
|
],
|
|
lesser = [ for (i = [0:1:len(arr)-1]) if (compare[i] < 0) arr[i] ],
|
|
equal = [ for (i = [0:1:len(arr)-1]) if (compare[i] ==0) arr[i] ],
|
|
greater = [ for (i = [0:1:len(arr)-1]) if (compare[i] > 0) arr[i] ]
|
|
)
|
|
concat(_sort_general(lesser,idx), equal, _sort_general(greater,idx));
|
|
|
|
|
|
// Function: sort()
|
|
// Usage:
|
|
// sort(list, [idx])
|
|
// Description:
|
|
// Sorts the given list using `compare_vals()`, sorting in lexicographic order, with types ordered according to
|
|
// `undef < boolean < number < string < list`. Comparison of lists is recursive.
|
|
// If the list is a list of vectors whose length is from 1 to 4 and the `idx` parameter is not passed, then
|
|
// `sort` uses a much more efficient method for comparisons and will run much faster. In this case, all entries
|
|
// in the data are compared using the native comparison operator, so comparisons between types will fail.
|
|
// Arguments:
|
|
// list = The list to sort.
|
|
// idx = If given, do the comparison based just on the specified index, range or list of indices.
|
|
// Example:
|
|
// l = [45,2,16,37,8,3,9,23,89,12,34];
|
|
// sorted = sort(l); // Returns [2,3,8,9,12,16,23,34,37,45,89]
|
|
function sort(list, idx=undef) =
|
|
!is_list(list) || len(list)<=1 ? list :
|
|
is_def(idx) ? _sort_general(list,idx) :
|
|
let(size = array_dim(list))
|
|
len(size)==1 ? _sort_scalars(list) :
|
|
len(size)==2 && size[1] <=4 ? (
|
|
size[1]==0 ? list :
|
|
size[1]==1 ? _sort_vectors1(list) :
|
|
size[1]==2 ? _sort_vectors2(list) :
|
|
size[1]==3 ? _sort_vectors3(list) :
|
|
/*size[1]==4*/ _sort_vectors4(list)
|
|
) : _sort_general(list);
|
|
|
|
|
|
// Function: sortidx()
|
|
// Description:
|
|
// Given a list, calculates the sort order of the list, and returns
|
|
// a list of indexes into the original list in that sorted order.
|
|
// If you iterate the returned list in order, and use the list items
|
|
// to index into the original list, you will be iterating the original
|
|
// values in sorted order.
|
|
// Example:
|
|
// lst = ["d","b","e","c"];
|
|
// idxs = sortidx(lst); // Returns: [1,3,0,2]
|
|
// ordered = select(lst, idxs); // Returns: ["b", "c", "d", "e"]
|
|
// Example:
|
|
// lst = [
|
|
// ["foo", 88, [0,0,1], false],
|
|
// ["bar", 90, [0,1,0], true],
|
|
// ["baz", 89, [1,0,0], false],
|
|
// ["qux", 23, [1,1,1], true]
|
|
// ];
|
|
// idxs1 = sortidx(lst, idx=1); // Returns: [3,0,2,1]
|
|
// idxs2 = sortidx(lst, idx=0); // Returns: [1,2,0,3]
|
|
// idxs3 = sortidx(lst, idx=[1,3]); // Returns: [3,0,2,1]
|
|
function sortidx(list, idx=undef) =
|
|
list==[] ? [] : let(
|
|
size = array_dim(list),
|
|
aug = is_undef(idx) && (len(size) == 1 || (len(size) == 2 && size[1]<=4))?
|
|
zip(list, list_range(len(list))) :
|
|
enumerate(list,idx=idx)
|
|
)
|
|
is_undef(idx) && len(size) == 1? subindex(_sort_vectors1(aug),1) :
|
|
is_undef(idx) && len(size) == 2 && size[1] <=4? (
|
|
size[1]==0? list_range(len(arr)) :
|
|
size[1]==1? subindex(_sort_vectors1(aug),1) :
|
|
size[1]==2? subindex(_sort_vectors2(aug),2) :
|
|
size[1]==3? subindex(_sort_vectors3(aug),3) :
|
|
/*size[1]==4*/ subindex(_sort_vectors4(aug),4)
|
|
) :
|
|
// general case
|
|
subindex(_sort_general(aug, idx=list_range(s=1,n=len(aug)-1)), 0);
|
|
|
|
|
|
// Function: unique()
|
|
// Usage:
|
|
// unique(arr);
|
|
// Description:
|
|
// Returns a sorted list with all repeated items removed.
|
|
// Arguments:
|
|
// arr = The list to uniquify.
|
|
function unique(arr) =
|
|
assert(is_list(arr)||is_string(arr))
|
|
len(arr)<=1? arr : let(
|
|
sorted = sort(arr)
|
|
) [
|
|
for (i=[0:1:len(sorted)-1])
|
|
if (i==0 || (sorted[i] != sorted[i-1]))
|
|
sorted[i]
|
|
];
|
|
|
|
|
|
// Function: unique_count()
|
|
// Usage:
|
|
// unique_count(arr);
|
|
// Description:
|
|
// Returns `[sorted,counts]` where `sorted` is a sorted list of the unique items in `arr` and `counts` is a list such
|
|
// that `count[i]` gives the number of times that `sorted[i]` appears in `arr`.
|
|
// Arguments:
|
|
// arr = The list to analyze.
|
|
function unique_count(arr) =
|
|
assert(is_list(arr) || is_string(arr))
|
|
arr == [] ? [[],[]] :
|
|
let( arr=sort(arr) )
|
|
let(ind = [0,for(i=[1:1:len(arr)-1]) if (arr[i]!=arr[i-1]) i])
|
|
[select(arr,ind),
|
|
deltas(concat(ind,[len(arr)]))];
|
|
|
|
// Section: List Iteration Helpers
|
|
|
|
// Function: idx()
|
|
// Usage:
|
|
// i = idx(list);
|
|
// for(i=idx(list)) ...
|
|
// Description:
|
|
// Returns the range of indexes for the given list.
|
|
// Arguments:
|
|
// list = The list to returns the index range of.
|
|
// step = The step size to stride through the list. Default: 1
|
|
// end = The delta from the end of the list. Default: -1
|
|
// start = The starting index. Default: 0
|
|
// Example(2D):
|
|
// colors = ["red", "green", "blue"];
|
|
// for (i=idx(colors)) right(20*i) color(colors[i]) circle(d=10);
|
|
function idx(list, step=1, end=-1,start=0) =
|
|
assert(is_list(list)||is_string(list))
|
|
[start : step : len(list)+end];
|
|
|
|
|
|
// Function: enumerate()
|
|
// Description:
|
|
// Returns a list, with each item of the given list `l` numbered in a sublist.
|
|
// Something like: `[[0,l[0]], [1,l[1]], [2,l[2]], ...]`
|
|
// Arguments:
|
|
// l = List to enumerate.
|
|
// idx = If given, enumerates just the given subindex items of `l`.
|
|
// Example:
|
|
// enumerate(["a","b","c"]); // Returns: [[0,"a"], [1,"b"], [2,"c"]]
|
|
// enumerate([[88,"a"],[76,"b"],[21,"c"]], idx=1); // Returns: [[0,"a"], [1,"b"], [2,"c"]]
|
|
// enumerate([["cat","a",12],["dog","b",10],["log","c",14]], idx=[1:2]); // Returns: [[0,"a",12], [1,"b",10], [2,"c",14]]
|
|
// Example(2D):
|
|
// colors = ["red", "green", "blue"];
|
|
// for (p=enumerate(colors)) right(20*p[0]) color(p[1]) circle(d=10);
|
|
function enumerate(l,idx=undef) =
|
|
assert(is_list(l)||is_string(list))
|
|
(idx==undef)?
|
|
[for (i=[0:1:len(l)-1]) [i,l[i]]] :
|
|
[for (i=[0:1:len(l)-1]) concat([i], [for (j=idx) l[i][j]])];
|
|
|
|
|
|
// Function: force_list()
|
|
// Usage:
|
|
// list = force_list(value)
|
|
// Description:
|
|
// If value is a list returns value, otherwise returns [value]. Makes it easy to
|
|
// treat a scalar input consistently as a singleton list along with list inputs.
|
|
function force_list(value) = is_list(value) ? value : [value];
|
|
|
|
|
|
// Function: pair()
|
|
// Usage:
|
|
// pair(v)
|
|
// Description:
|
|
// Takes a list, and returns a list of adjacent pairs from it.
|
|
// Example:
|
|
// l = ["A","B","C",D"];
|
|
// echo([for (p=pair(l)) str(p.y,p.x)]); // Outputs: ["BA", "CB", "DC"]
|
|
function pair(v) =
|
|
assert(is_list(v)||is_string(v))
|
|
[for (i=[0:1:len(v)-2]) [v[i],v[i+1]]];
|
|
|
|
|
|
// Function: pair_wrap()
|
|
// Usage:
|
|
// pair_wrap(v)
|
|
// Description:
|
|
// Takes a list, and returns a list of adjacent pairss from it, wrapping around from the end to the start of the list.
|
|
// Example:
|
|
// l = ["A","B","C","D"];
|
|
// echo([for (p=pair_wrap(l)) str(p.y,p.x)]); // Outputs: ["BA", "CB", "DC", "AD"]
|
|
function pair_wrap(v) =
|
|
assert(is_list(v)||is_string(v))
|
|
[for (i=[0:1:len(v)-1]) [v[i],v[(i+1)%len(v)]]];
|
|
|
|
|
|
// Function: triplet()
|
|
// Usage:
|
|
// triplet(v)
|
|
// Description:
|
|
// Takes a list, and returns a list of adjacent triplets from it.
|
|
// Example:
|
|
// l = ["A","B","C","D","E"];
|
|
// echo([for (p=triplet(l)) str(p.z,p.y,p.x)]); // Outputs: ["CBA", "DCB", "EDC"]
|
|
function triplet(v) =
|
|
assert(is_list(v)||is_string(v))
|
|
[for (i=[0:1:len(v)-3]) [v[i],v[i+1],v[i+2]]];
|
|
|
|
|
|
// Function: triplet_wrap()
|
|
// Usage:
|
|
// triplet_wrap(v)
|
|
// Description:
|
|
// Takes a list, and returns a list of adjacent triplets from it, wrapping around from the end to the start of the list.
|
|
// Example:
|
|
// l = ["A","B","C","D"];
|
|
// echo([for (p=triplet_wrap(l)) str(p.z,p.y,p.x)]); // Outputs: ["CBA", "DCB", "ADC", "BAD"]
|
|
function triplet_wrap(v) =
|
|
assert(is_list(v)||is_string(v))
|
|
[for (i=[0:1:len(v)-1]) [v[i],v[(i+1)%len(v)],v[(i+2)%len(v)]]];
|
|
|
|
|
|
// Function: permute()
|
|
// Usage:
|
|
// list = permute(l, [n]);
|
|
// Description:
|
|
// Returns an ordered list of every unique permutation of `n` items out of the given list `l`.
|
|
// For the list `[1,2,3,4]`, with `n=2`, this will return `[[1,2], [1,3], [1,4], [2,3], [2,4], [3,4]]`.
|
|
// For the list `[1,2,3,4]`, with `n=3`, this will return `[[1,2,3], [1,2,4], [1,3,4], [2,3,4]]`.
|
|
// Arguments:
|
|
// l = The list to provide permutations for.
|
|
// n = The number of items in each permutation. Default: 2
|
|
// Example:
|
|
// pairs = permute([3,4,5,6]); // Returns: [[3,4],[3,5],[3,6],[4,5],[4,6],[5,6]]
|
|
// triplets = permute([3,4,5,6],n=3); // Returns: [[3,4,5],[3,4,6],[3,5,6],[4,5,6]]
|
|
// Example(2D):
|
|
// for (p=permute(regular_ngon(n=7,d=100))) stroke(p);
|
|
function permute(l,n=2,_s=0) =
|
|
assert(is_list(l))
|
|
assert(len(l)-_s >= n)
|
|
n==1? [for (i=[_s:1:len(l)-1]) [l[i]]] :
|
|
[for (i=[_s:1:len(l)-n], p=permute(l,n=n-1,_s=i+1)) concat([l[i]], p)];
|
|
|
|
|
|
// Section: Array Manipulation
|
|
|
|
// Function: subindex()
|
|
// Description:
|
|
// For each array item, return the indexed subitem.
|
|
// Returns a list of the values of each vector at the specfied
|
|
// index list or range. If the index list or range has
|
|
// only one entry the output list is flattened.
|
|
// Arguments:
|
|
// v = The given list of lists.
|
|
// idx = The index, list of indices, or range of indices to fetch.
|
|
// Example:
|
|
// v = [[[1,2,3,4],[5,6,7,8],[9,10,11,12],[13,14,15,16]];
|
|
// subindex(v,2); // Returns [3, 7, 11, 15]
|
|
// subindex(v,[2,1]); // Returns [[3, 2], [7, 6], [11, 10], [15, 14]]
|
|
// subindex(v,[1:3]); // Returns [[2, 3, 4], [6, 7, 8], [10, 11, 12], [14, 15, 16]]
|
|
function subindex(v, idx) = [
|
|
for(val=v) let(value=[for(i=idx) val[i]])
|
|
len(value)==1 ? value[0] : value
|
|
];
|
|
|
|
|
|
// Function: zip()
|
|
// Usage:
|
|
// zip(v1, v2, v3, [fit], [fill]);
|
|
// zip(vecs, [fit], [fill]);
|
|
// Description:
|
|
// Zips together corresponding items from two or more lists.
|
|
// Returns a list of lists, where each sublist contains corresponding
|
|
// items from each of the input lists. `[[A1, B1, C1], [A2, B2, C2], ...]`
|
|
// Arguments:
|
|
// vecs = A list of two or more lists to zipper together.
|
|
// fit = If `fit=="short"`, the zips together up to the length of the shortest list in vecs. If `fit=="long"`, then pads all lists to the length of the longest, using the value in `fill`. If `fit==false`, then requires all lists to be the same length. Default: false.
|
|
// fill = The default value to fill in with if one or more lists if short. Default: undef
|
|
// Example:
|
|
// v1 = [1,2,3,4];
|
|
// v2 = [5,6,7];
|
|
// v3 = [8,9,10,11];
|
|
// zip(v1,v3); // returns [[1,8], [2,9], [3,10], [4,11]]
|
|
// zip([v1,v3]); // returns [[1,8], [2,9], [3,10], [4,11]]
|
|
// zip([v1,v2], fit="short"); // returns [[1,5], [2,6], [3,7]]
|
|
// zip([v1,v2], fit="long"); // returns [[1,5], [2,6], [3,7], [4,undef]]
|
|
// zip([v1,v2], fit="long, fill=0); // returns [[1,5], [2,6], [3,7], [4,0]]
|
|
// zip([v1,v2,v3], fit="long"); // returns [[1,5,8], [2,6,9], [3,7,10], [4,undef,11]]
|
|
// Example:
|
|
// v1 = [[1,2,3], [4,5,6], [7,8,9]];
|
|
// v2 = [[20,19,18], [17,16,15], [14,13,12]];
|
|
// zip(v1,v2); // Returns [[1,2,3,20,19,18], [4,5,6,17,16,15], [7,8,9,14,13,12]]
|
|
function zip(vecs, v2, v3, fit=false, fill=undef) =
|
|
(v3!=undef)? zip([vecs,v2,v3], fit=fit, fill=fill) :
|
|
(v2!=undef)? zip([vecs,v2], fit=fit, fill=fill) :
|
|
assert(in_list(fit, [false, "short", "long"]))
|
|
assert(all([for(v=vecs) is_list(v)]), "One of the inputs to zip is not a list")
|
|
let(
|
|
minlen = list_shortest(vecs),
|
|
maxlen = list_longest(vecs),
|
|
dummy = (fit==false)? assert(minlen==maxlen, "Input vectors to zip must have the same length") : 0
|
|
) (fit == "long")?
|
|
[for(i=[0:1:maxlen-1]) [for(v=vecs) for(x=(i<len(v)? v[i] : (fill==undef)? [fill] : fill)) x] ] :
|
|
[for(i=[0:1:minlen-1]) [for(v=vecs) for(x=v[i]) x] ];
|
|
|
|
|
|
// Function: array_group()
|
|
// Description:
|
|
// Takes a flat array of values, and groups items in sets of `cnt` length.
|
|
// The opposite of this is `flatten()`.
|
|
// Arguments:
|
|
// v = The list of items to group.
|
|
// cnt = The number of items to put in each grouping.
|
|
// dflt = The default value to fill in with is the list is not a multiple of `cnt` items long.
|
|
// Example:
|
|
// v = [1,2,3,4,5,6];
|
|
// array_group(v,2) returns [[1,2], [3,4], [5,6]]
|
|
// array_group(v,3) returns [[1,2,3], [4,5,6]]
|
|
// array_group(v,4,0) returns [[1,2,3,4], [5,6,0,0]]
|
|
function array_group(v, cnt=2, dflt=0) = [for (i = [0:cnt:len(v)-1]) [for (j = [0:1:cnt-1]) default(v[i+j], dflt)]];
|
|
|
|
|
|
// Function: flatten()
|
|
// Description: Takes a list of lists and flattens it by one level.
|
|
// Arguments:
|
|
// l = List to flatten.
|
|
// Example:
|
|
// flatten([[1,2,3], [4,5,[6,7,8]]]) returns [1,2,3,4,5,[6,7,8]]
|
|
function flatten(l) = [for (a = l) each a];
|
|
|
|
|
|
// Internal. Not exposed.
|
|
function _array_dim_recurse(v) =
|
|
!is_list(v[0])? (
|
|
sum( [for(entry=v) is_list(entry) ? 1 : 0]) == 0 ? [] : [undef]
|
|
) : let(
|
|
firstlen = len(v[0]),
|
|
first = sum( [for(entry = v) len(entry) == firstlen ? 0 : 1] ) == 0 ? firstlen : undef,
|
|
leveldown = flatten(v)
|
|
) is_list(leveldown[0])? (
|
|
concat([first],_array_dim_recurse(leveldown))
|
|
) : [first];
|
|
|
|
|
|
// Function: array_dim()
|
|
// Usage:
|
|
// array_dim(v, [depth])
|
|
// Description:
|
|
// Returns the size of a multi-dimensional array. Returns a list of
|
|
// dimension lengths. The length of `v` is the dimension `0`. The
|
|
// length of the items in `v` is dimension `1`. The length of the
|
|
// items in the items in `v` is dimension `2`, etc. For each dimension,
|
|
// if the length of items at that depth is inconsistent, `undef` will
|
|
// be returned. If no items of that dimension depth exist, `0` is
|
|
// returned. Otherwise, the consistent length of items in that
|
|
// dimensional depth is returned.
|
|
// Arguments:
|
|
// v = Array to get dimensions of.
|
|
// depth = Dimension to get size of. If not given, returns a list of dimension lengths.
|
|
// Examples:
|
|
// array_dim([[[1,2,3],[4,5,6]],[[7,8,9],[10,11,12]]]); // Returns [2,2,3]
|
|
// array_dim([[[1,2,3],[4,5,6]],[[7,8,9],[10,11,12]]], 0); // Returns 2
|
|
// array_dim([[[1,2,3],[4,5,6]],[[7,8,9],[10,11,12]]], 2); // Returns 3
|
|
// array_dim([[[1,2,3],[4,5,6]],[[7,8,9]]]); // Returns [2,undef,3]
|
|
function array_dim(v, depth=undef) =
|
|
(depth == undef)? (
|
|
concat([len(v)], _array_dim_recurse(v))
|
|
) : (depth == 0)? (
|
|
len(v)
|
|
) : (
|
|
let(dimlist = _array_dim_recurse(v))
|
|
(depth > len(dimlist))? 0 : dimlist[depth-1]
|
|
);
|
|
|
|
|
|
|
|
// Function: transpose()
|
|
// Description: Returns the transposition of the given array.
|
|
// Example:
|
|
// arr = [
|
|
// ["a", "b", "c"],
|
|
// ["d", "e", "f"],
|
|
// ["g", "h", "i"]
|
|
// ];
|
|
// t = transpose(arr);
|
|
// // Returns:
|
|
// // [
|
|
// // ["a", "d", "g"],
|
|
// // ["b", "e", "h"],
|
|
// // ["c", "f", "i"],
|
|
// // ]
|
|
// Example:
|
|
// arr = [
|
|
// ["a", "b", "c"],
|
|
// ["d", "e", "f"]
|
|
// ];
|
|
// t = transpose(arr);
|
|
// // Returns:
|
|
// // [
|
|
// // ["a", "d"],
|
|
// // ["b", "e"],
|
|
// // ["c", "f"],
|
|
// // ]
|
|
// Example:
|
|
// transpose([3,4,5]); // Returns: [3,4,5]
|
|
function transpose(arr) =
|
|
is_list(arr[0])? [for (i=[0:1:len(arr[0])-1]) [for (j=[0:1:len(arr)-1]) arr[j][i]]] : arr;
|
|
|
|
|
|
|
|
|
|
// vim: noexpandtab tabstop=4 shiftwidth=4 softtabstop=4 nowrap
|