# HG changeset patch
# User Nicholas R. Jankowski <jankowskin@asme.org>
# Date 1632445601 14400
# Node ID 54774a713d7c71a1f4e21f2d8c0ae8b7cbe24ffd
# Parent  8f61866f0f6d50727604680dd74e8b2b9c1c8dc1
nchoosek.m: Improve struct input handling for k<n (bug #61119)

* nchoosek.m: replace call to repelems with repelem to handle struct inputs for
k<n.  Add k<n struct BIST test.

diff -r 8f61866f0f6d -r 54774a713d7c scripts/specfun/nchoosek.m
--- a/scripts/specfun/nchoosek.m	Fri Sep 24 17:58:38 2021 +0200
+++ b/scripts/specfun/nchoosek.m	Thu Sep 23 21:06:41 2021 -0400
@@ -127,7 +127,7 @@
     C = v(zeros (0, k));  # return 0xk object for Matlab compatibility
   elseif (k == 2)
     ## Can do it without transpose.
-    x = repelems (v(1:n-1), [1:n-1; n-1:-1:1]).';
+    x = repelem (v(1:n-1), [n-1:-1:1]).';
     y = cat (1, cellslices (v(:), 2:n, n*ones (1, n-1)){:});
     C = [x, y];
   elseif (k < n)
@@ -138,7 +138,7 @@
       c = columns (C);
       cA = cellslices (C, l, c*ones (1, n-k+1), 2);
       l = c-l+1;
-      b = repelems (v(k-j+1:n-j+1), [1:n-k+1; l]);
+      b = repelem (v(k-j+1:n-j+1), l);
       C = [b; cA{:}];
       l = cumsum (l);
       l = [1, 1 + l(1:n-k)];
@@ -160,8 +160,8 @@
 %!test
 %! s(1).a = 1;
 %! s(2).a = 2;
-%! assert (nchoosek (s, 1), s(:)); 
-%! assert (nchoosek (s, 2), s); 
+%! assert (nchoosek (s, 1), s(:));
+%! assert (nchoosek (s, 2), s);
 
 # Verify Matlab compatibility of return sizes & types
 %!test
@@ -228,12 +228,17 @@
 %! s.a = [1 2 3];
 %! s.b = [4 5 6];
 %! s(2).a = 1;  # make s a struct array rather than scalar struct
+%! s(3).b = 2;  # make s at least three elements for k == 2 test below
 %! x = nchoosek (s, 0);
 %! assert (size (x), [1, 0]);
 %! assert (isstruct (x));
 %! assert (fieldnames (x), {"a"; "b"});
-%! x = nchoosek (s, 3);
-%! assert (size (x), [0, 3]);
+%! x = nchoosek (s, 2);
+%! assert (size (x), [3, 2]);
+%! assert (isstruct (x));
+%! assert (fieldnames (x), {"a"; "b"});
+%! x = nchoosek (s, 4);
+%! assert (size (x), [0, 4]);
 %! assert (isstruct (x));
 %! assert (fieldnames (x), {"a"; "b"});