Added median()

math.scad

@@ -519,8 +519,8 @@ function product(v, i=0, tot=undef) = i>=len(v)? tot : product(v, i+1, ((tot==un
 
 // Function: mean()
 // Description:
-//   Returns the mean of all entries in the given array.
+//   Returns the arithmatic mean/average of all entries in the given array.
-//   If passed an array of vectors, returns a vector of mean of each part.
+//   If passed a list of vectors, returns a vector of the mean of each part.
 // Arguments:
 //   v = The list of values to get the mean of.
 // Example:
@@ -529,6 +529,25 @@ function product(v, i=0, tot=undef) = i>=len(v)? tot : product(v, i+1, ((tot==un
 function mean(v) = sum(v)/len(v);
 
 
+// Function: median()
+// Usage:
+//   x = median(v);
+// Description:
+//   Given a list of numbers or vectors, finds the median value or midpoint.
+//   If passed a list of vectors, returns the vector of the median of each part.
+function median(v) =
+	assert(is_list(v))
+	assert(len(v)>0)
+	is_vector(v[0])? (
+		assert(is_consistent(v))
+		[
+			for (i=idx(v[0]))
+			let(vals = subindex(v,i))
+			(min(vals)+max(vals))/2
+		]
+	) : (min(v)+max(v))/2;
+
+
 // Section: Matrix math
 
 // Function: linear_solve()
@@ -546,15 +565,15 @@ function linear_solve(A,b) =
 	)
 	assert(len(b)==m,str("Incompatible matrix and vector",dim,len(b)))
 	let (
-		qr = m<n ? qr_factor(transpose(A)) : qr_factor(A),
+		qr = m<n? qr_factor(transpose(A)) : qr_factor(A),
 		maxdim = max(n,m),
 		mindim = min(n,m),
 		Q = submatrix(qr[0],[0:maxdim-1], [0:mindim-1]),
 		R = submatrix(qr[1],[0:mindim-1], [0:mindim-1]),
 		zeros = [for(i=[0:mindim-1]) if (approx(R[i][i],0)) i]
 	)
-	zeros != [] ? undef :
+	zeros != []? undef :
-	m<n ? Q*back_substitute(R,b,transpose=true) :
+	m<n? Q*back_substitute(R,b,transpose=true) :
 	back_substitute(R, transpose(Q)*b);
 
 

version.scad

@@ -8,7 +8,7 @@
 //////////////////////////////////////////////////////////////////////
 
 
-BOSL_VERSION = [2,0,197];
+BOSL_VERSION = [2,0,198];
 
 
 // Section: BOSL Library Version Functions