mirror of
https://github.com/BelfrySCAD/BOSL2.git
synced 2024-12-29 00:09:41 +00:00
1168 lines
46 KiB
OpenSCAD
1168 lines
46 KiB
OpenSCAD
//////////////////////////////////////////////////////////////////////
|
|
// LibFile: lists.scad
|
|
// Functions for constructing and manipulating generic lists.
|
|
// Includes:
|
|
// include <BOSL2/std.scad>
|
|
//////////////////////////////////////////////////////////////////////
|
|
|
|
// Terminology:
|
|
// **List** = An ordered collection of zero or more items. ie: `["a", "b", "c"]`
|
|
// **Vector** = A list of numbers. ie: `[4, 5, 6]`
|
|
// **Array** = A nested list of lists, or list of lists of lists, or deeper. ie: `[[2,3], [4,5], [6,7]]`
|
|
// **Set** = A list of unique items.
|
|
|
|
|
|
// Section: List Query Operations
|
|
|
|
|
|
// Function: is_homogeneous()
|
|
// Alias: is_homogenous()
|
|
// Usage:
|
|
// bool = is_homogeneous(list, depth);
|
|
// Topics: List Handling, Type Checking
|
|
// See Also: is_vector(), is_matrix()
|
|
// Description:
|
|
// Returns true when the list has elements of same type up to the depth `depth`.
|
|
// Booleans and numbers are not distinguinshed as of distinct types.
|
|
// Arguments:
|
|
// l = the list to check
|
|
// depth = the lowest level the check is done
|
|
// Example:
|
|
// a = is_homogeneous([[1,["a"]], [2,["b"]]]); // Returns true
|
|
// b = is_homogeneous([[1,["a"]], [2,[true]]]); // Returns false
|
|
// c = is_homogeneous([[1,["a"]], [2,[true]]], 1); // Returns true
|
|
// d = is_homogeneous([[1,["a"]], [2,[true]]], 2); // Returns false
|
|
// e = is_homogeneous([[1,["a"]], [true,["b"]]]); // Returns true
|
|
function is_homogeneous(l, depth=10) =
|
|
!is_list(l) || l==[] ? false :
|
|
let( l0=l[0] )
|
|
[] == [for(i=[1:1:len(l)-1]) if( ! _same_type(l[i],l0, depth+1) ) 0 ];
|
|
|
|
function is_homogenous(l, depth=10) = is_homogeneous(l, depth);
|
|
|
|
|
|
function _same_type(a,b, depth) =
|
|
(depth==0) ||
|
|
(is_undef(a) && is_undef(b)) ||
|
|
(is_bool(a) && is_bool(b)) ||
|
|
(is_num(a) && is_num(b)) ||
|
|
(is_string(a) && is_string(b)) ||
|
|
(is_list(a) && is_list(b) && len(a)==len(b)
|
|
&& []==[for(i=idx(a)) if( ! _same_type(a[i],b[i],depth-1) ) 0] );
|
|
|
|
|
|
// Function: min_length()
|
|
// Usage:
|
|
// llen = min_length(array);
|
|
// Topics: List Handling
|
|
// See Also: max_length()
|
|
// Description:
|
|
// Returns the length of the shortest sublist in a list of lists.
|
|
// Arguments:
|
|
// array = A list of lists.
|
|
// Example:
|
|
// slen = min_length([[3,4,5],[6,7,8,9]]); // Returns: 3
|
|
function min_length(array) =
|
|
assert(is_list(array), "Invalid input." )
|
|
min([for (v = array) len(v)]);
|
|
|
|
|
|
// Function: max_length()
|
|
// Usage:
|
|
// llen = max_length(array);
|
|
// Topics: List Handling
|
|
// See Also: min_length()
|
|
// Description:
|
|
// Returns the length of the longest sublist in a list of lists.
|
|
// Arguments:
|
|
// array = A list of lists.
|
|
// Example:
|
|
// llen = max_length([[3,4,5],[6,7,8,9]]); // Returns: 4
|
|
function max_length(array) =
|
|
assert(is_list(array), "Invalid input." )
|
|
max([for (v = array) len(v)]);
|
|
|
|
|
|
|
|
|
|
// Internal. Not exposed.
|
|
function _list_shape_recurse(v) =
|
|
!is_list(v[0])
|
|
? len( [for(entry=v) if(!is_list(entry)) 0] ) == 0 ? [] : [undef]
|
|
: let(
|
|
firstlen = is_list(v[0]) ? len(v[0]): undef,
|
|
first = len( [for(entry = v) if(! is_list(entry) || (len(entry) != firstlen)) 0 ] ) == 0 ? firstlen : undef,
|
|
leveldown = flatten(v)
|
|
)
|
|
is_list(leveldown[0])
|
|
? concat([first],_list_shape_recurse(leveldown))
|
|
: [first];
|
|
|
|
function _list_shape_recurse(v) =
|
|
let( alen = [for(vi=v) is_list(vi) ? len(vi): -1] )
|
|
v==[] || max(alen)==-1 ? [] :
|
|
let( add = max(alen)!=min(alen) ? undef : alen[0] )
|
|
concat( add, _list_shape_recurse(flatten(v)));
|
|
|
|
|
|
// Function: list_shape()
|
|
// Usage:
|
|
// dims = list_shape(v, [depth]);
|
|
// Topics: Matrices, Array Handling
|
|
// Description:
|
|
// Returns the size of a multi-dimensional array, a list of the lengths at each depth.
|
|
// If the returned value has `dims[i] = j` then it means the ith index ranges of j items.
|
|
// The return `dims[0]` is equal to the length of v. Then `dims[1]` is equal to the
|
|
// length of the lists in v, and in general, `dims[i]` is equal to the length of the items
|
|
// nested to depth i in the list v. If the length of items at that depth is inconsistent, then
|
|
// `undef` is returned. If no items exist at that depth then `0` is returned. Note that
|
|
// for simple vectors or matrices it is faster to compute `len(v)` and `len(v[0])`.
|
|
// Arguments:
|
|
// v = list to get shape of
|
|
// depth = depth to compute the size of. If not given, returns a list of sizes at all depths.
|
|
// Example:
|
|
// a = list_shape([[[1,2,3],[4,5,6]],[[7,8,9],[10,11,12]]]); // Returns [2,2,3]
|
|
// b = list_shape([[[1,2,3],[4,5,6]],[[7,8,9],[10,11,12]]], 0); // Returns 2
|
|
// c = list_shape([[[1,2,3],[4,5,6]],[[7,8,9],[10,11,12]]], 2); // Returns 3
|
|
// d = list_shape([[[1,2,3],[4,5,6]],[[7,8,9]]]); // Returns [2,undef,3]
|
|
function list_shape(v, depth=undef) =
|
|
assert( is_undef(depth) || ( is_finite(depth) && depth>=0 ), "Invalid depth.")
|
|
! is_list(v) ? 0 :
|
|
(depth == undef)
|
|
? concat([len(v)], _list_shape_recurse(v))
|
|
: (depth == 0)
|
|
? len(v)
|
|
: let( dimlist = _list_shape_recurse(v))
|
|
(depth > len(dimlist))? 0 : dimlist[depth-1] ;
|
|
|
|
|
|
|
|
// Function: in_list()
|
|
// Usage:
|
|
// bool = in_list(val, list, [idx]);
|
|
// Topics: List Handling
|
|
// Description:
|
|
// Returns true if value `val` is in list `list`. When `val==NAN` the answer will be false for any list.
|
|
// Arguments:
|
|
// val = The simple value to search for.
|
|
// list = The list to search.
|
|
// idx = If given, searches the given columns for matches for `val`.
|
|
// Example:
|
|
// a = in_list("bar", ["foo", "bar", "baz"]); // Returns true.
|
|
// b = in_list("bee", ["foo", "bar", "baz"]); // Returns false.
|
|
// c = in_list("bar", [[2,"foo"], [4,"bar"], [3,"baz"]], idx=1); // Returns true.
|
|
|
|
// Note that a huge complication occurs because OpenSCAD's search() finds
|
|
// index i as a hits if the val equals list[i] but also if val equals list[i][0].
|
|
// This means every hit needs to be checked to see if it's actually a hit,
|
|
// and if the first hit is a mismatch we have to keep searching.
|
|
// We assume that the normal case doesn't have mixed data, and try first
|
|
// with just one hit, but if this finds a mismatch then we try again
|
|
// with all hits, which could be slow for long lists.
|
|
function in_list(val,list,idx) =
|
|
assert(is_list(list),"Input is not a list")
|
|
assert(is_undef(idx) || is_finite(idx), "Invalid idx value.")
|
|
let( firsthit = search([val], list, num_returns_per_match=1, index_col_num=idx)[0] )
|
|
firsthit==[] ? false
|
|
: is_undef(idx) && val==list[firsthit] ? true
|
|
: is_def(idx) && val==list[firsthit][idx] ? true
|
|
// first hit was found but didn't match, so try again with all hits
|
|
: let ( allhits = search([val], list, 0, idx)[0])
|
|
is_undef(idx) ? [for(hit=allhits) if (list[hit]==val) 1] != []
|
|
: [for(hit=allhits) if (list[hit][idx]==val) 1] != [];
|
|
|
|
|
|
|
|
// Section: List Indexing
|
|
|
|
// Function: select()
|
|
// Topics: List Handling
|
|
// Description:
|
|
// Returns a portion of a list, wrapping around past the beginning, if end<start.
|
|
// The first item is index 0. Negative indexes are counted back from the end.
|
|
// The last item is -1. If only the `start` index is given, returns just the value
|
|
// at that position when `start` is a number or the selected list of entries when `start` is
|
|
// a list of indices or a range.
|
|
// Usage:
|
|
// item = select(list, start);
|
|
// item = select(list, [s:d:e]);
|
|
// item = select(list, [i0,i1...,ik]);
|
|
// list = select(list, start, end);
|
|
// Arguments:
|
|
// list = The list to get the portion of.
|
|
// start = Either the index of the first item or an index range or a list of indices.
|
|
// end = The index of the last item when `start` is a number. When `start` is a list or a range, `end` should not be given.
|
|
// See Also: slice(), column(), last()
|
|
// Example:
|
|
// l = [3,4,5,6,7,8,9];
|
|
// a = select(l, 5, 6); // Returns [8,9]
|
|
// b = select(l, 5, 8); // Returns [8,9,3,4]
|
|
// c = select(l, 5, 2); // Returns [8,9,3,4,5]
|
|
// d = select(l, -3, -1); // Returns [7,8,9]
|
|
// e = select(l, 3, 3); // Returns [6]
|
|
// f = select(l, 4); // Returns 7
|
|
// g = select(l, -2); // Returns 8
|
|
// h = select(l, [1:3]); // Returns [4,5,6]
|
|
// i = select(l, [3,1]); // Returns [6,4]
|
|
function select(list, start, end) =
|
|
assert( is_list(list) || is_string(list), "Invalid list.")
|
|
let(l=len(list))
|
|
l==0
|
|
? []
|
|
: end==undef
|
|
? is_num(start)
|
|
? list[ (start%l+l)%l ]
|
|
: assert( start==[] || is_vector(start) || is_range(start), "Invalid start parameter")
|
|
[for (i=start) list[ (i%l+l)%l ] ]
|
|
: assert(is_finite(start), "When `end` is given, `start` parameter should be a number.")
|
|
assert(is_finite(end), "Invalid end parameter.")
|
|
let( s = (start%l+l)%l, e = (end%l+l)%l )
|
|
(s <= e)
|
|
? [ for (i = [s:1:e]) list[i] ]
|
|
: [ for (i = [s:1:l-1]) list[i],
|
|
for (i = [0:1:e]) list[i] ] ;
|
|
|
|
|
|
// Function: slice()
|
|
// Usage:
|
|
// list = slice(list, s, e);
|
|
// Description:
|
|
// Returns a slice of a list, from the first position `s` up to and including the last position `e`.
|
|
// The first item in the list is at index 0. Negative indexes are counted back from the end.
|
|
// An index of -1 refers to the last list item.
|
|
// Arguments:
|
|
// list = The list to get the slice of.
|
|
// s = The index of the first item to return.
|
|
// e = The index of the last item to return.
|
|
// See Also: select(), column(), last()
|
|
// Example:
|
|
// a = slice([3,4,5,6,7,8,9], 3, 5); // Returns [6,7,8]
|
|
// b = slice([3,4,5,6,7,8,9], 2, -1); // Returns [5,6,7,8,9]
|
|
// c = slice([3,4,5,6,7,8,9], 1, 1); // Returns [4]
|
|
// d = slice([3,4,5,6,7,8,9], 5); // Returns [8,9]
|
|
// e = slice([3,4,5,6,7,8,9], 2, -2); // Returns [5,6,7,8]
|
|
// f = slice([3,4,5,6,7,8,9], 4, 3; // Returns []
|
|
function slice(list,s=0,e=-1) =
|
|
assert(is_list(list))
|
|
assert(is_int(s))
|
|
assert(is_int(e))
|
|
!list? [] :
|
|
let(
|
|
l = len(list),
|
|
s = constrain(s + (s<0? l : 0), 0, l-1),
|
|
e = constrain(e + (e<0? l : 0), 0, l-1)
|
|
)
|
|
[if (e>=s) for (i=[s:1:e]) list[i]];
|
|
|
|
|
|
// Function: last()
|
|
// Usage:
|
|
// item = last(list);
|
|
// Topics: List Handling
|
|
// See Also: select(), slice(), column()
|
|
// Description:
|
|
// Returns the last element of a list, or undef if empty.
|
|
// Arguments:
|
|
// list = The list to get the last element of.
|
|
// Example:
|
|
// l = [3,4,5,6,7,8,9];
|
|
// x = last(l); // Returns 9.
|
|
function last(list) =
|
|
list[len(list)-1];
|
|
|
|
|
|
// Function: list_head()
|
|
// Usage:
|
|
// list = list_head(list, [to]);
|
|
// Topics: List Handling
|
|
// See Also: select(), slice(), list_tail(), last()
|
|
// Description:
|
|
// Returns the head of the given list, from the first item up until the `to` index, inclusive.
|
|
// If the `to` index is negative, then the length of the list is added to it, such that
|
|
// `-1` is the last list item. `-2` is the second from last. `-3` is third from last, etc.
|
|
// If the list is shorter than the given index, then the full list is returned.
|
|
// Arguments:
|
|
// list = The list to get the head of.
|
|
// to = The last index to include. If negative, adds the list length to it. ie: -1 is the last list item.
|
|
// Example:
|
|
// hlist1 = list_head(["foo", "bar", "baz"]); // Returns: ["foo", "bar"]
|
|
// hlist2 = list_head(["foo", "bar", "baz"], -3); // Returns: ["foo"]
|
|
// hlist3 = list_head(["foo", "bar", "baz"], 2); // Returns: ["foo","bar"]
|
|
// hlist4 = list_head(["foo", "bar", "baz"], -5); // Returns: []
|
|
// hlist5 = list_head(["foo", "bar", "baz"], 5); // Returns: ["foo","bar","baz"]
|
|
function list_head(list, to=-2) =
|
|
assert(is_list(list))
|
|
assert(is_finite(to))
|
|
to<0? [for (i=[0:1:len(list)+to]) list[i]] :
|
|
to<len(list)? [for (i=[0:1:to]) list[i]] :
|
|
list;
|
|
|
|
|
|
// Function: list_tail()
|
|
// Usage:
|
|
// list = list_tail(list, [from]);
|
|
// Topics: List Handling
|
|
// See Also: select(), slice(), list_tail(), last()
|
|
// Description:
|
|
// Returns the tail of the given list, from the `from` index up until the end of the list, inclusive.
|
|
// If the `from` index is negative, then the length of the list is added to it, such that
|
|
// `-1` is the last list item. `-2` is the second from last. `-3` is third from last, etc.
|
|
// If you want it to return the last three items of the list, use `from=-3`.
|
|
// Arguments:
|
|
// list = The list to get the tail of.
|
|
// from = The first index to include. If negative, adds the list length to it. ie: -1 is the last list item.
|
|
// Example:
|
|
// tlist1 = list_tail(["foo", "bar", "baz"]); // Returns: ["bar", "baz"]
|
|
// tlist2 = list_tail(["foo", "bar", "baz"], -1); // Returns: ["baz"]
|
|
// tlist3 = list_tail(["foo", "bar", "baz"], 2); // Returns: ["baz"]
|
|
// tlist4 = list_tail(["foo", "bar", "baz"], -5); // Returns: ["foo","bar","baz"]
|
|
// tlist5 = list_tail(["foo", "bar", "baz"], 5); // Returns: []
|
|
function list_tail(list, from=1) =
|
|
assert(is_list(list))
|
|
assert(is_finite(from))
|
|
from>=0? [for (i=[from:1:len(list)-1]) list[i]] :
|
|
let(from = from + len(list))
|
|
from>=0? [for (i=[from:1:len(list)-1]) list[i]] :
|
|
list;
|
|
|
|
|
|
|
|
// Function: bselect()
|
|
// Usage:
|
|
// array = bselect(array, index);
|
|
// Topics: List Handling
|
|
// See Also: list_bset()
|
|
// 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:
|
|
// a = 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), "Improper array." )
|
|
assert(is_list(index) && len(index)>=len(array) , "Improper index list." )
|
|
is_string(array)? str_join(bselect( [for (x=array) x], index)) :
|
|
[for(i=[0:len(array)-1]) if (index[i]) array[i]];
|
|
|
|
|
|
|
|
|
|
|
|
// Section: List Construction
|
|
|
|
|
|
// Function: repeat()
|
|
// Usage:
|
|
// list = repeat(val, n);
|
|
// Topics: List Handling
|
|
// See Also: count(), lerpn()
|
|
// Description:
|
|
// Generates a list or array of `n` copies of the given value `val`.
|
|
// If the count `n` is given as a list of counts, then this creates a
|
|
// multi-dimensional array, filled with `val`.
|
|
// Arguments:
|
|
// val = The value to repeat to make the list or array.
|
|
// n = The number of copies to make of `val`.
|
|
// Example:
|
|
// a = repeat(1, 4); // Returns [1,1,1,1]
|
|
// b = repeat(8, [2,3]); // Returns [[8,8,8], [8,8,8]]
|
|
// c = repeat(0, [2,2,3]); // Returns [[[0,0,0],[0,0,0]], [[0,0,0],[0,0,0]]]
|
|
// d = repeat([1,2,3],3); // Returns [[1,2,3], [1,2,3], [1,2,3]]
|
|
function repeat(val, n, i=0) =
|
|
is_num(n)? [for(j=[1:1:n]) val] :
|
|
assert( is_list(n), "Invalid count number.")
|
|
(i>=len(n))? val :
|
|
[for (j=[1:1:n[i]]) repeat(val, n, i+1)];
|
|
|
|
|
|
// Function: count()
|
|
// Usage:
|
|
// list = count(n, [s], [step], [reverse]);
|
|
// Description:
|
|
// Creates a list of `n` numbers, starting at `s`, incrementing by `step` each time.
|
|
// You can also pass a list for n and then the length of the input list is used.
|
|
// Arguments:
|
|
// n = The length of the list of numbers to create, or a list to match the length of
|
|
// s = The starting value of the list of numbers.
|
|
// step = The amount to increment successive numbers in the list.
|
|
// reverse = Reverse the list. Default: false.
|
|
// Example:
|
|
// nl1 = count(5); // Returns: [0,1,2,3,4]
|
|
// nl2 = count(5,3); // Returns: [3,4,5,6,7]
|
|
// nl3 = count(4,3,2); // Returns: [3,5,7,9]
|
|
// nl4 = count(5,reverse=true); // Returns: [4,3,2,1,0]
|
|
// nl5 = count(5,3,reverse=true); // Returns: [7,6,5,4,3]
|
|
function count(n,s=0,step=1,reverse=false) = let(n=is_list(n) ? len(n) : n)
|
|
reverse? [for (i=[n-1:-1:0]) s+i*step]
|
|
: [for (i=[0:1:n-1]) s+i*step];
|
|
|
|
|
|
|
|
// Function: list_bset()
|
|
// Usage:
|
|
// arr = list_bset(indexset, valuelist, [dflt]);
|
|
// Topics: List Handling
|
|
// See Also: bselect()
|
|
// 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 the item is 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:
|
|
// a = list_bset([false,true,false,true,false], [3,4]); // Returns: [0,3,0,4,0]
|
|
// b = 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), "The index set is not a list." )
|
|
assert(is_list(valuelist), "The `valuelist` is not a list." )
|
|
let( trueind = search([true], indexset,0)[0] )
|
|
assert( !(len(trueind)>len(valuelist)), str("List `valuelist` too short; its length should be ",len(trueind)) )
|
|
assert( !(len(trueind)<len(valuelist)), str("List `valuelist` too long; its length should be ",len(trueind)) )
|
|
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
|
|
);
|
|
|
|
|
|
|
|
// Function: list()
|
|
// Topics: List Handling, Type Conversion
|
|
// Usage:
|
|
// list = list(l)
|
|
// Description:
|
|
// Expands a range into a full list. If given a list, returns it verbatim.
|
|
// If given a string, explodes it into a list of single letters.
|
|
// Arguments:
|
|
// l = The value to expand.
|
|
// See Also: scalar_vec3(), force_list()
|
|
// Example:
|
|
// l1 = list([3:2:9]); // Returns: [3,5,7,9]
|
|
// l2 = list([3,4,5]); // Returns: [3,4,5]
|
|
// l3 = list("Foo"); // Returns: ["F","o","o"]
|
|
// l4 = list(23); // Returns: [23]
|
|
function list(l) = is_list(l)? l : [for (x=l) x];
|
|
|
|
|
|
// Function: force_list()
|
|
// Usage:
|
|
// list = force_list(value, [n], [fill]);
|
|
// Topics: List Handling
|
|
// See Also: scalar_vec3()
|
|
// Description:
|
|
// Coerces non-list values into a list. Makes it easy to treat a scalar input
|
|
// consistently as a singleton list, as well as list inputs.
|
|
// - If `value` is a list, then that list is returned verbatim.
|
|
// - If `value` is not a list, and `fill` is not given, then a list of `n` copies of `value` will be returned.
|
|
// - If `value` is not a list, and `fill` is given, then a list `n` items long will be returned where `value` will be the first item, and the rest will contain the value of `fill`.
|
|
// Arguments:
|
|
// value = The value or list to coerce into a list.
|
|
// n = The number of items in the coerced list. Default: 1
|
|
// fill = The value to pad the coerced list with, after the firt value. Default: undef (pad with copies of `value`)
|
|
// Example:
|
|
// x = force_list([3,4,5]); // Returns: [3,4,5]
|
|
// y = force_list(5); // Returns: [5]
|
|
// z = force_list(7, n=3); // Returns: [7,7,7]
|
|
// w = force_list(4, n=3, fill=1); // Returns: [4,1,1]
|
|
function force_list(value, n=1, fill) =
|
|
is_list(value) ? value :
|
|
is_undef(fill)? [for (i=[1:1:n]) value] : [value, for (i=[2:1:n]) fill];
|
|
|
|
|
|
// Section: List Modification
|
|
|
|
// Function: reverse()
|
|
// Usage:
|
|
// rlist = reverse(list);
|
|
// Topics: List Handling
|
|
// See Also: select(), list_rotate()
|
|
// Description:
|
|
// Reverses a list/array or string.
|
|
// Arguments:
|
|
// x = The list or string to reverse.
|
|
// Example:
|
|
// reverse([3,4,5,6]); // Returns [6,5,4,3]
|
|
function reverse(x) =
|
|
assert(is_list(x)||is_string(x), str("Input to reverse must be a list or string. Got: ",x))
|
|
let (elems = [ for (i = [len(x)-1 : -1 : 0]) x[i] ])
|
|
is_string(x)? str_join(elems) : elems;
|
|
|
|
|
|
// Function: list_rotate()
|
|
// Usage:
|
|
// rlist = list_rotate(list, [n]);
|
|
// Topics: List Handling
|
|
// See Also: select(), reverse()
|
|
// Description:
|
|
// Rotates the contents of a list by `n` positions left.
|
|
// If `n` is negative, then the rotation is `abs(n)` positions to the right.
|
|
// If `list` is a string, then a string is returned with the characters rotates within the string.
|
|
// Arguments:
|
|
// list = The list to rotate.
|
|
// n = The number of positions to rotate by. If negative, rotated to the right. Positive rotates to the left. Default: 1
|
|
// Example:
|
|
// l1 = list_rotate([1,2,3,4,5],-2); // Returns: [4,5,1,2,3]
|
|
// l2 = list_rotate([1,2,3,4,5],-1); // Returns: [5,1,2,3,4]
|
|
// l3 = list_rotate([1,2,3,4,5],0); // Returns: [1,2,3,4,5]
|
|
// l4 = list_rotate([1,2,3,4,5],1); // Returns: [2,3,4,5,1]
|
|
// l5 = list_rotate([1,2,3,4,5],2); // Returns: [3,4,5,1,2]
|
|
// l6 = list_rotate([1,2,3,4,5],3); // Returns: [4,5,1,2,3]
|
|
// l7 = list_rotate([1,2,3,4,5],4); // Returns: [5,1,2,3,4]
|
|
// l8 = list_rotate([1,2,3,4,5],5); // Returns: [1,2,3,4,5]
|
|
// l9 = list_rotate([1,2,3,4,5],6); // Returns: [2,3,4,5,1]
|
|
function list_rotate(list,n=1) =
|
|
assert(is_list(list)||is_string(list), "Invalid list or string.")
|
|
assert(is_int(n), "The rotation number should be integer")
|
|
let (
|
|
ll = len(list),
|
|
n = ((n % ll) + ll) % ll,
|
|
elems = [
|
|
for (i=[n:1:ll-1]) list[i],
|
|
for (i=[0:1:n-1]) list[i]
|
|
]
|
|
)
|
|
is_string(list)? str_join(elems) : elems;
|
|
|
|
|
|
|
|
// Function: shuffle()
|
|
// Usage:
|
|
// shuffled = shuffle(list, [seed]);
|
|
// Topics: List Handling
|
|
// See Also: sort(), sortidx(), unique(), unique_count()
|
|
// Description:
|
|
// Shuffles the input list into random order.
|
|
// If given a string, shuffles the characters within the string.
|
|
// If you give a numeric seed value then the permutation
|
|
// will be repeatable.
|
|
// Arguments:
|
|
// list = The list to shuffle.
|
|
// seed = Optional random number seed for the shuffling.
|
|
// Example:
|
|
// // Spades Hearts Diamonds Clubs
|
|
// suits = ["\u2660", "\u2661", "\u2662", "\u2663"];
|
|
// ranks = [2,3,4,5,6,7,8,9,10,"J","Q","K","A"];
|
|
// cards = [for (suit=suits, rank=ranks) str(rank,suit)];
|
|
// deck = shuffle(cards);
|
|
function shuffle(list,seed) =
|
|
assert(is_list(list)||is_string(list), "Invalid input." )
|
|
is_string(list)? str_join(shuffle([for (x = list) x],seed=seed)) :
|
|
len(list)<=1 ? list :
|
|
let(
|
|
rval = is_num(seed) ? rands(0,1,len(list),seed_value=seed)
|
|
: 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));
|
|
|
|
|
|
|
|
// Function: repeat_entries()
|
|
// Usage:
|
|
// newlist = repeat_entries(list, N, [exact]);
|
|
// Topics: List Handling
|
|
// See Also: repeat()
|
|
// Description:
|
|
// Takes a list as input and duplicates some of its entries to produce a list
|
|
// with length `N`. If the requested `N` is not a multiple of the list length then
|
|
// the entries will be duplicated as uniformly as possible. You can also set `N` to a vector,
|
|
// in which case len(N) must equal len(list) and the output repeats the ith entry N[i] times.
|
|
// In either case, the result will be a list of length `N`. The `exact` option requires
|
|
// that the final length is exactly as requested. If you set it to `false` then the
|
|
// algorithm will favor uniformity and the output list may have a different number of
|
|
// entries due to rounding.
|
|
// .
|
|
// When applied to a path the output path is the same geometrical shape but has some vertices
|
|
// repeated. This can be useful when you need to align paths with a different number of points.
|
|
// (See also subdivide_path for a different way to do that.)
|
|
// Arguments:
|
|
// list = list whose entries will be repeated
|
|
// N = scalar total number of points desired or vector requesting N[i] copies of vertex i.
|
|
// 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
|
|
// Example:
|
|
// list = [0,1,2,3];
|
|
// a = repeat_entries(list, 6); // Returns: [0,0,1,2,2,3]
|
|
// b = repeat_entries(list, 6, exact=false); // Returns: [0,0,1,1,2,2,3,3]
|
|
// c = repeat_entries(list, [1,1,2,1], exact=false); // Returns: [0,1,2,2,3]
|
|
function repeat_entries(list, N, exact=true) =
|
|
assert(is_list(list) && len(list)>0, "The list cannot be void.")
|
|
assert((is_finite(N) && N>0) || is_vector(N,len(list)),
|
|
"Parameter N must be a number greater than zero or vector with the same length of `list`")
|
|
let(
|
|
length = len(list),
|
|
reps_guess = is_list(N)? N : repeat(N/length,length),
|
|
reps = exact ?
|
|
_sum_preserving_round(reps_guess)
|
|
: [for (val=reps_guess) round(val)]
|
|
)
|
|
[for(i=[0:length-1]) each repeat(list[i],reps[i])];
|
|
|
|
|
|
// Function: list_pad()
|
|
// Usage:
|
|
// arr = list_pad(array, minlen, [fill]);
|
|
// Topics: List Handling
|
|
// See Also: force_list(), scalar_vec3()
|
|
// Description:
|
|
// If the list `array` is shorter than `minlen` length, pad it to length with the value given in `fill`.
|
|
// Arguments:
|
|
// array = A list.
|
|
// minlen = The minimum length to pad the list to.
|
|
// fill = The value to pad the list with. Default: `undef`
|
|
// Example:
|
|
// list = [3,4,5];
|
|
// nlist = list_pad(list,5,23); // Returns: [3,4,5,23,23]
|
|
function list_pad(array, minlen, fill) =
|
|
assert(is_list(array), "Invalid input." )
|
|
concat(array,repeat(fill,minlen-len(array)));
|
|
|
|
|
|
// Function: list_set()
|
|
// Usage:
|
|
// list = list_set(list, indices, values, [dflt], [minlen]);
|
|
// Topics: List Handling
|
|
// See Also: list_insert(), list_remove(), list_remove_values()
|
|
// Description:
|
|
// Takes the input list and returns a new list such that `list[indices[i]] = values[i]` for all of
|
|
// the (index,value) pairs supplied and unchanged for other indices. If you supply `indices` that are
|
|
// beyond the length of the list then the list is extended and filled in with the `dflt` value.
|
|
// If you set `minlen` then the list is lengthed, if necessary, by padding with `dflt` to that length.
|
|
// Repetitions in `indices` are not allowed. The lists `indices` and `values` must have the same length.
|
|
// If `indices` is given as a scalar, then that index of the given `list` will be set to the scalar value of `values`.
|
|
// Arguments:
|
|
// list = List to set items in. Default: []
|
|
// indices = List of indices into `list` to set.
|
|
// values = List of values to set.
|
|
// dflt = Default value to store in sparse skipped indices.
|
|
// minlen = Minimum length to expand list to.
|
|
// Example:
|
|
// a = list_set([2,3,4,5], 2, 21); // Returns: [2,3,21,5]
|
|
// b = list_set([2,3,4,5], [1,3], [81,47]); // Returns: [2,81,4,47]
|
|
function list_set(list=[],indices,values,dflt=0,minlen=0) =
|
|
assert(is_list(list))
|
|
!is_list(indices)? (
|
|
(is_finite(indices) && indices<len(list))
|
|
? concat([for (i=idx(list)) i==indices? values : list[i]], repeat(dflt, minlen-len(list)))
|
|
: list_set(list,[indices],[values],dflt)
|
|
) :
|
|
indices==[] && values==[]
|
|
? concat(list, repeat(dflt, minlen-len(list)))
|
|
: assert(is_vector(indices) && is_list(values) && len(values)==len(indices),
|
|
"Index list and value list must have the same length")
|
|
let( midx = max(len(list)-1, max(indices)) )
|
|
[
|
|
for (i=[0:1:midx]) let(
|
|
j = search(i,indices,0),
|
|
k = j[0]
|
|
)
|
|
assert( len(j)<2, "Repeated indices are not allowed." )
|
|
k!=undef
|
|
? values[k]
|
|
: i<len(list) ? list[i] : dflt,
|
|
each repeat(dflt, minlen-max(len(list),max(indices)))
|
|
];
|
|
|
|
|
|
// Function: list_insert()
|
|
// Usage:
|
|
// list = list_insert(list, indices, values);
|
|
// Topics: List Handling
|
|
// See Also: list_set(), list_remove(), list_remove_values()
|
|
// Description:
|
|
// Insert `values` into `list` before position `indices`.
|
|
// Example:
|
|
// a = list_insert([3,6,9,12],1,5); // Returns [3,5,6,9,12]
|
|
// b = list_insert([3,6,9,12],[1,3],[5,11]); // Returns [3,5,6,9,11,12]
|
|
function list_insert(list, indices, values) =
|
|
assert(is_list(list))
|
|
!is_list(indices) ?
|
|
assert( is_finite(indices) && is_finite(values), "Invalid indices/values." )
|
|
assert( indices<=len(list), "Indices must be <= len(list) ." )
|
|
[
|
|
for (i=idx(list)) each ( i==indices? [ values, list[i] ] : [ list[i] ] ),
|
|
if (indices==len(list)) values
|
|
] :
|
|
indices==[] && values==[] ? list :
|
|
assert( is_vector(indices) && is_list(values) && len(values)==len(indices),
|
|
"Index list and value list must have the same length")
|
|
assert( max(indices)<=len(list), "Indices must be <= len(list)." )
|
|
let(
|
|
maxidx = max(indices),
|
|
minidx = min(indices)
|
|
) [
|
|
for (i=[0:1:minidx-1] ) list[i],
|
|
for (i=[minidx : min(maxidx, len(list)-1)] )
|
|
let(
|
|
j = search(i,indices,0),
|
|
k = j[0],
|
|
x = assert( len(j)<2, "Repeated indices are not allowed." )
|
|
) each ( k != undef ? [ values[k], list[i] ] : [ list[i] ] ),
|
|
for ( i = [min(maxidx, len(list)-1)+1 : 1 : len(list)-1] ) list[i],
|
|
if (maxidx == len(list)) values[max_index(indices)]
|
|
];
|
|
|
|
|
|
// Function: list_remove()
|
|
// Usage:
|
|
// list = list_remove(list, ind);
|
|
// Topics: List Handling
|
|
// See Also: list_set(), list_insert(), list_remove_values()
|
|
// Description:
|
|
// If `ind` is a number remove `list[ind]` from the list. If `ind` is a list of indices
|
|
// remove from the list the item all items whose indices appear in `ind`. If you give
|
|
// indices that are not in the list they are ignored.
|
|
// Arguments:
|
|
// list = The list to remove items from.
|
|
// ind = index or list of indices of items to remove.
|
|
// Example:
|
|
// a = list_remove([3,6,9,12],1); // Returns: [3,9,12]
|
|
// b = list_remove([3,6,9,12],[1,3]); // Returns: [3,9]
|
|
// c = list_remove([3,6],3); // Returns: [3,6]
|
|
function list_remove(list, ind) =
|
|
assert(is_list(list), "Invalid list in list_remove")
|
|
is_finite(ind) ?
|
|
(
|
|
(ind<0 || ind>=len(list)) ? list
|
|
:
|
|
[
|
|
for (i=[0:1:ind-1]) list[i],
|
|
for (i=[ind+1:1:len(list)-1]) list[i]
|
|
]
|
|
)
|
|
: ind==[] ? list
|
|
: assert( is_vector(ind), "Invalid index list in list_remove")
|
|
let(sres = search(count(list),ind,1))
|
|
[
|
|
for(i=idx(list))
|
|
if (sres[i] == [])
|
|
list[i]
|
|
];
|
|
|
|
// This method is faster for long lists with few values to remove
|
|
// let( rem = list_set([], indices, repeat(1,len(indices)), minlen=len(list)))
|
|
// [for(i=idx(list)) if (rem[i]==0) list[i]];
|
|
|
|
|
|
|
|
// Function: list_remove_values()
|
|
// Usage:
|
|
// list = list_remove_values(list, values);
|
|
// list = list_remove_values(list, values, all=true);
|
|
// Topics: List Handling
|
|
// See Also: list_set(), list_insert(), list_remove()
|
|
// Description:
|
|
// Removes the first, or all instances of the given value or list of values from the list.
|
|
// If you specify `all=false` and list a value twice then the first two instances will be removed.
|
|
// Note that if you want to remove a list value such as `[3,4]` then you must give it as
|
|
// a singleton list, or it will be interpreted as a list of two scalars to remove.
|
|
// Arguments:
|
|
// list = The list to modify.
|
|
// values = The value or list of 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:
|
|
// test = [3,4,[5,6],7,5,[5,6],4,[6,5],7,[4,4]];
|
|
// a=list_remove_values(test,4); // Returns: [3, [5, 6], 7, 5, [5, 6], 4, [6, 5], 7, [4, 4]]
|
|
// b=list_remove_values(test,[4,4]); // Returns: [3, [5, 6], 7, 5, [5, 6], [6, 5], 7, [4, 4]]
|
|
// c=list_remove_values(test,[4,7]); // Returns: [3, [5, 6], 5, [5, 6], 4, [6, 5], 7, [4, 4]]
|
|
// d=list_remove_values(test,[5,6]); // Returns: [3, 4, [5, 6], 7, [5, 6], 4, [6, 5], 7, [4, 4]]
|
|
// e=list_remove_values(test,[[5,6]]); // Returns: [3,4,7,5,[5,6],4,[6,5],7,[4,4]]
|
|
// f=list_remove_values(test,[[5,6]],all=true); // Returns: [3,4,7,5,4,[6,5],7,[4,4]]
|
|
// 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) =
|
|
!is_list(values)? list_remove_values(list, values=[values], all=all) :
|
|
assert(is_list(list), "Invalid list")
|
|
len(values)==0 ? list :
|
|
len(values)==1 ?
|
|
(
|
|
!all ?
|
|
(
|
|
let(firsthit = search(values,list,1)[0])
|
|
firsthit==[] ? list
|
|
: list[firsthit]==values[0] ? list_remove(list,firsthit)
|
|
: let(allhits = search(values,list,0)[0],
|
|
allind = [for(i=allhits) if (list[i]==values[0]) i]
|
|
)
|
|
allind==[] ? list : list_remove(list,min(allind))
|
|
)
|
|
:
|
|
(
|
|
let(allhits = search(values,list,0)[0],
|
|
allind = [for(i=allhits) if (list[i]==values[0]) i]
|
|
)
|
|
allind==[] ? list : list_remove(list,allind)
|
|
)
|
|
)
|
|
:!all ? list_remove_values(list_remove_values(list, values[0],all=all), list_tail(values),all=all)
|
|
:
|
|
[
|
|
for(i=idx(list))
|
|
let(hit=search([list[i]],values,0)[0])
|
|
if (hit==[]) list[i]
|
|
else
|
|
let(check = [for(j=hit) if (values[j]==list[i]) 1])
|
|
if (check==[]) list[i]
|
|
];
|
|
|
|
|
|
|
|
|
|
// Section: Iteration Helpers
|
|
|
|
// Function: idx()
|
|
// Usage:
|
|
// rng = idx(list, [s=], [e=], [step=]);
|
|
// for(i=idx(list, [s=], [e=], [step=])) ...
|
|
// Topics: List Handling, Iteration
|
|
// See Also: enumerate(), pair(), triplet(), combinations(), permutations()
|
|
// Description:
|
|
// Returns the range of indexes for the given list.
|
|
// Arguments:
|
|
// list = The list to returns the index range of.
|
|
// s = The starting index. Default: 0
|
|
// e = The delta from the end of the list. Default: -1 (end of list)
|
|
// step = The step size to stride through the list. Default: 1
|
|
// Example(2D):
|
|
// colors = ["red", "green", "blue"];
|
|
// for (i=idx(colors)) right(20*i) color(colors[i]) circle(d=10);
|
|
function idx(list, s=0, e=-1, step=1) =
|
|
assert(is_list(list)||is_string(list), "Invalid input." )
|
|
let( ll = len(list) )
|
|
ll == 0 ? [0:1:ll-1] :
|
|
let(
|
|
_s = posmod(s,ll),
|
|
_e = posmod(e,ll)
|
|
) [_s : step : _e];
|
|
|
|
|
|
// Function: enumerate()
|
|
// Usage:
|
|
// arr = enumerate(l, [idx]);
|
|
// for (x = enumerate(l, [idx])) ... // x[0] is the index number, x[1] is the item.
|
|
// Topics: List Handling, Iteration
|
|
// See Also: idx(), pair(), triplet(), combinations(), permutations()
|
|
// 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 columns 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), "Invalid input." )
|
|
assert( _valid_idx(idx,0,len(l)), "Invalid index/indices." )
|
|
(idx==undef)
|
|
? [for (i=[0:1:len(l)-1]) [i,l[i]]]
|
|
: [for (i=[0:1:len(l)-1]) [ i, for (j=idx) l[i][j]] ];
|
|
|
|
|
|
// Function: pair()
|
|
// Usage:
|
|
// p = pair(list, [wrap]);
|
|
// for (p = pair(list, [wrap])) ... // On each iteration, p contains a list of two adjacent items.
|
|
// Topics: List Handling, Iteration
|
|
// See Also: idx(), enumerate(), triplet(), combinations(), permutations()
|
|
// Description:
|
|
// Takes a list, and returns a list of adjacent pairs from it, optionally wrapping back to the front.
|
|
// Arguments:
|
|
// list = The list to iterate.
|
|
// wrap = If true, wrap back to the start from the end. ie: return the last and first items as the last pair. Default: false
|
|
// Example(2D): Does NOT wrap from end to start,
|
|
// for (p = pair(circle(d=40, $fn=12)))
|
|
// stroke(p, endcap2="arrow2");
|
|
// Example(2D): Wraps around from end to start.
|
|
// for (p = pair(circle(d=40, $fn=12), wrap=true))
|
|
// stroke(p, endcap2="arrow2");
|
|
// Example:
|
|
// l = ["A","B","C","D"];
|
|
// echo([for (p=pair(l)) str(p.y,p.x)]); // Outputs: ["BA", "CB", "DC"]
|
|
function pair(list, wrap=false) =
|
|
assert(is_list(list)||is_string(list), "Invalid input." )
|
|
assert(is_bool(wrap))
|
|
let( L = len(list)-1)
|
|
L<1 ? [] :
|
|
[
|
|
for (i=[0:1:L-1]) [list[i], list[i+1]],
|
|
if(wrap) [list[L], list[0]]
|
|
];
|
|
|
|
|
|
|
|
// Function: triplet()
|
|
// Usage:
|
|
// list = triplet(list, [wrap]);
|
|
// for (t = triplet(list, [wrap])) ...
|
|
// Topics: List Handling, Iteration
|
|
// See Also: idx(), enumerate(), pair(), combinations(), permutations()
|
|
// Description:
|
|
// Takes a list, and returns a list of adjacent triplets from it, optionally wrapping back to the front.
|
|
// If you set `wrap` to true then the first triplet is the one centered on the first list element, so it includes
|
|
// the last element and the first two elements. If the list has fewer than three elements then the empty list is returned.
|
|
// Arguments:
|
|
// list = list to produce triplets from
|
|
// wrap = if true, wrap triplets around the list. Default: false
|
|
// Example:
|
|
// list = [0,1,2,3,4];
|
|
// a = triplet(list); // Returns [[0,1,2],[1,2,3],[2,3,4]]
|
|
// b = triplet(list,wrap=true); // Returns [[4,0,1],[0,1,2],[1,2,3],[2,3,4],[3,4,0]]
|
|
// letters = ["A","B","C","D","E"];
|
|
// [for (p=triplet(letters)) str(p.z,p.y,p.x)]; // Returns: ["CBA", "DCB", "EDC"]
|
|
// Example(2D):
|
|
// path = [for (i=[0:24]) polar_to_xy(i*2, i*360/12)];
|
|
// for (t = triplet(path)) {
|
|
// a = t[0]; b = t[1]; c = t[2];
|
|
// v = unit(unit(a-b) + unit(c-b));
|
|
// translate(b) rot(from=FWD,to=v) anchor_arrow2d();
|
|
// }
|
|
// stroke(path);
|
|
function triplet(list, wrap=false) =
|
|
assert(is_list(list)||is_string(list), "Invalid input." )
|
|
assert(is_bool(wrap))
|
|
let(L=len(list))
|
|
L<3 ? [] :
|
|
[
|
|
if(wrap) [list[L-1], list[0], list[1]],
|
|
for (i=[0:1:L-3]) [list[i],list[i+1],list[i+2]],
|
|
if(wrap) [list[L-2], list[L-1], list[0]]
|
|
];
|
|
|
|
|
|
// Function: combinations()
|
|
// Usage:
|
|
// list = combinations(l, [n]);
|
|
// Topics: List Handling, Iteration
|
|
// See Also: idx(), enumerate(), pair(), triplet(), permutations()
|
|
// Description:
|
|
// Returns a list of all of the (unordered) combinations 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 = combinations([3,4,5,6]); // Returns: [[3,4],[3,5],[3,6],[4,5],[4,6],[5,6]]
|
|
// triplets = combinations([3,4,5,6],n=3); // Returns: [[3,4,5],[3,4,6],[3,5,6],[4,5,6]]
|
|
// Example(2D):
|
|
// for (p=combinations(regular_ngon(n=7,d=100))) stroke(p);
|
|
function combinations(l,n=2,_s=0) =
|
|
assert(is_list(l), "Invalid list." )
|
|
assert( is_finite(n) && n>=1 && n<=len(l), "Invalid number `n`." )
|
|
n==1
|
|
? [for (i=[_s:1:len(l)-1]) [l[i]]]
|
|
: [for (i=[_s:1:len(l)-n], p=combinations(l,n=n-1,_s=i+1)) concat([l[i]], p)];
|
|
|
|
|
|
// Function: permutations()
|
|
// Usage:
|
|
// list = permutations(l, [n]);
|
|
// Topics: List Handling, Iteration
|
|
// See Also: idx(), enumerate(), pair(), triplet(), combinations()
|
|
// Description:
|
|
// Returns a list of all of the (ordered) permutation `n` items out of the given list `l`.
|
|
// For the list `[1,2,3]`, with `n=2`, this will return `[[1,2],[1,3],[2,1],[2,3],[3,1],[3,2]]`
|
|
// For the list `[1,2,3]`, with `n=3`, this will return `[[1,2,3],[1,3,2],[2,1,3],[2,3,1],[3,1,2],[3,2,1]]`
|
|
// Arguments:
|
|
// l = The list to provide permutations for.
|
|
// n = The number of items in each permutation. Default: 2
|
|
// Example:
|
|
// pairs = permutations([3,4,5,6]); // // Returns: [[3,4],[3,5],[3,6],[4,3],[4,5],[4,6],[5,3],[5,4],[5,6],[6,3],[6,4],[6,5]]
|
|
function permutations(l,n=2) =
|
|
assert(is_list(l), "Invalid list." )
|
|
assert( is_finite(n) && n>=1 && n<=len(l), "Invalid number `n`." )
|
|
n==1
|
|
? [for (i=[0:1:len(l)-1]) [l[i]]]
|
|
: [for (i=idx(l), p=permutations([for (j=idx(l)) if (i!=j) l[j]], n=n-1)) concat([l[i]], p)];
|
|
|
|
|
|
|
|
|
|
|
|
// Section: Changing list structure
|
|
|
|
|
|
// Function: list_to_matrix()
|
|
// Usage:
|
|
// groups = list_to_matrix(v, [cnt], [dflt]);
|
|
// Description:
|
|
// Takes a flat array of values, and groups items in sets of `cnt` length.
|
|
// The opposite of this is `flatten()`.
|
|
// Topics: Matrices, Array Handling
|
|
// See Also: column(), submatrix(), hstack(), flatten(), full_flatten()
|
|
// Arguments:
|
|
// v = The list of items to group.
|
|
// cnt = The number of items to put in each grouping. Default:2
|
|
// dflt = The default value to fill in with if the list is not a multiple of `cnt` items long. Default: 0
|
|
// Example:
|
|
// v = [1,2,3,4,5,6];
|
|
// a = list_to_matrix(v,2) returns [[1,2], [3,4], [5,6]]
|
|
// b = list_to_matrix(v,3) returns [[1,2,3], [4,5,6]]
|
|
// c = list_to_matrix(v,4,0) returns [[1,2,3,4], [5,6,0,0]]
|
|
function list_to_matrix(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()
|
|
// Usage:
|
|
// list = flatten(l);
|
|
// Topics: Matrices, Array Handling
|
|
// See Also: column(), submatrix(), hstack(), full_flatten()
|
|
// Description:
|
|
// Takes a list of lists and flattens it by one level.
|
|
// Arguments:
|
|
// l = List to flatten.
|
|
// Example:
|
|
// l = flatten([[1,2,3], [4,5,[6,7,8]]]); // returns [1,2,3,4,5,[6,7,8]]
|
|
function flatten(l) =
|
|
!is_list(l)? l :
|
|
[for (a=l) if (is_list(a)) (each a) else a];
|
|
|
|
|
|
// Function: full_flatten()
|
|
// Usage:
|
|
// list = full_flatten(l);
|
|
// Topics: Matrices, Array Handling
|
|
// See Also: column(), submatrix(), hstack(), flatten()
|
|
// Description:
|
|
// Collects in a list all elements recursively found in any level of the given list.
|
|
// The output list is ordered in depth first order.
|
|
// Arguments:
|
|
// l = List to flatten.
|
|
// Example:
|
|
// l = full_flatten([[1,2,3], [4,5,[6,7,8]]]); // returns [1,2,3,4,5,6,7,8]
|
|
function full_flatten(l) =
|
|
!is_list(l)? l :
|
|
[for (a=l) if (is_list(a)) (each full_flatten(a)) else a];
|
|
|
|
|
|
|
|
// Function: zip()
|
|
// Usage:
|
|
// pairs = zip(a,b);
|
|
// triples = zip(a,b,c);
|
|
// quads = zip([LIST1,LIST2,LIST3,LIST4]);
|
|
// Topics: List Handling, Iteration
|
|
// Description:
|
|
// Zips together two or more lists into a single list. For example, if you have two
|
|
// lists [3,4,5], and [8,7,6], and zip them together, you get [ [3,8],[4,7],[5,6] ].
|
|
// The list returned will be as long as the shortest list passed to zip().
|
|
// Arguments:
|
|
// a = The first list, or a list of lists if b and c are not given.
|
|
// b = The second list, if given.
|
|
// c = The third list, if given.
|
|
// Example:
|
|
// a = [9,8,7,6]; b = [1,2,3];
|
|
// for (p=zip(a,b)) echo(p);
|
|
// // ECHO: [9,1]
|
|
// // ECHO: [8,2]
|
|
// // ECHO: [7,3]
|
|
function zip(a,b,c) =
|
|
b!=undef? zip([a,b,if (c!=undef) c]) :
|
|
let(n = min_length(a))
|
|
[for (i=[0:1:n-1]) [for (x=a) x[i]]];
|
|
|
|
|
|
|
|
// Section: Set Manipulation
|
|
|
|
// Function: set_union()
|
|
// Usage:
|
|
// s = set_union(a, b, [get_indices]);
|
|
// Topics: Set Handling, List Handling
|
|
// See Also: set_difference(), set_intersection()
|
|
// Description:
|
|
// Given two sets (lists with unique items), returns the set of unique items that are in either `a` or `b`.
|
|
// If `get_indices` is true, a list of indices into the new union set are returned for each item in `b`,
|
|
// in addition to returning the new union set. In this case, a 2-item list is returned, `[INDICES, NEWSET]`,
|
|
// where INDICES is the list of indices for items in `b`, and NEWSET is the new union set.
|
|
// Arguments:
|
|
// a = One of the two sets to merge.
|
|
// b = The other of the two sets to merge.
|
|
// get_indices = If true, indices into the new union set are also returned for each item in `b`. Returns `[INDICES, NEWSET]`. Default: false
|
|
// Example:
|
|
// set_a = [2,3,5,7,11];
|
|
// set_b = [1,2,3,5,8];
|
|
// set_u = set_union(set_a, set_b);
|
|
// // set_u now equals [2,3,5,7,11,1,8]
|
|
// set_v = set_union(set_a, set_b, get_indices=true);
|
|
// // set_v now equals [[5,0,1,2,6], [2,3,5,7,11,1,8]]
|
|
function set_union(a, b, get_indices=false) =
|
|
assert( is_list(a) && is_list(b), "Invalid sets." )
|
|
let(
|
|
found1 = search(b, a),
|
|
found2 = search(b, b),
|
|
c = [ for (i=idx(b))
|
|
if (found1[i] == [] && found2[i] == i)
|
|
b[i]
|
|
],
|
|
nset = concat(a, c)
|
|
)
|
|
! get_indices ? nset :
|
|
let(
|
|
la = len(a),
|
|
found3 = search(b, c),
|
|
idxs = [ for (i=idx(b))
|
|
(found1[i] != [])? found1[i] : la + found3[i]
|
|
]
|
|
) [idxs, nset];
|
|
|
|
|
|
// Function: set_difference()
|
|
// Usage:
|
|
// s = set_difference(a, b);
|
|
// Topics: Set Handling, List Handling
|
|
// See Also: set_union(), set_intersection()
|
|
// Description:
|
|
// Given two sets (lists with unique items), returns the set of items that are in `a`, but not `b`.
|
|
// Arguments:
|
|
// a = The starting set.
|
|
// b = The set of items to remove from set `a`.
|
|
// Example:
|
|
// set_a = [2,3,5,7,11];
|
|
// set_b = [1,2,3,5,8];
|
|
// set_d = set_difference(set_a, set_b);
|
|
// // set_d now equals [7,11]
|
|
function set_difference(a, b) =
|
|
assert( is_list(a) && is_list(b), "Invalid sets." )
|
|
let( found = search(a, b, num_returns_per_match=1) )
|
|
[ for (i=idx(a)) if(found[i]==[]) a[i] ];
|
|
|
|
|
|
// Function: set_intersection()
|
|
// Usage:
|
|
// s = set_intersection(a, b);
|
|
// Topics: Set Handling, List Handling
|
|
// See Also: set_union(), set_difference()
|
|
// Description:
|
|
// Given two sets (lists with unique items), returns the set of items that are in both sets.
|
|
// Arguments:
|
|
// a = The starting set.
|
|
// b = The set of items to intersect with set `a`.
|
|
// Example:
|
|
// set_a = [2,3,5,7,11];
|
|
// set_b = [1,2,3,5,8];
|
|
// set_i = set_intersection(set_a, set_b);
|
|
// // set_i now equals [2,3,5]
|
|
function set_intersection(a, b) =
|
|
assert( is_list(a) && is_list(b), "Invalid sets." )
|
|
let( found = search(a, b, num_returns_per_match=1) )
|
|
[ for (i=idx(a)) if(found[i]!=[]) a[i] ];
|
|
|
|
|
|
|
|
|
|
// vim: expandtab tabstop=4 shiftwidth=4 softtabstop=4 nowrap
|