diff general/arrutils/extract.m @ 4:e44f49929e56

Adding reorganised general toolbox, now in several subdirectories.

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/general/arrutils/extract.m	Sat Jan 12 19:21:22 2013 +0000
@@ -0,0 +1,25 @@
+% EXTRACT - Extract a sub-array
+%
+% extract :: 
+%	[[size:[E]]], 
+%	n:1..E, 
+%	[[2]->natural]~'start and end indices' 
+% -> [[size1:[E]].
+%
+% Examples (assuming A is 3D): 
+%	extract(A,2,[4 20]) = A(:,4:20,:)
+%	extract(A,3,[2 10]) = A(:,:,2:10)
+function y=extract(x,dim,range)
+
+	persistent colons
+
+	n=ndims(x);
+	if length(colons)<n,
+		colons=repmat({':'},1,n);
+	end
+
+	s=colons(1:n); %cell(1,n); s(:)={':'};
+	s{dim}=range(1):range(2);
+	S.type='()';
+	S.subs=s;
+	y=subsref(x,S);