# HG changeset patch
# User Etienne Grossmann <address@hidden>
# Date 1446094825 25200
#      Wed Oct 28 22:00:25 2015 -0700
# Node ID 68a0b0a6e06eb2fa36632ca6bd888d2866d5f75b
# Parent  226e9c81eb04fe18fb3c4fd85207c8c64dfb9e04
Hey, there's just one changed file wrt hg

diff -r 226e9c81eb04 -r 68a0b0a6e06e inst/checker_color.m
--- a/inst/checker_color.m	Tue Sep 03 07:50:42 2013 -0400
+++ b/inst/checker_color.m	Wed Oct 28 22:00:25 2015 -0700
@@ -13,10 +13,30 @@
 ## You should have received a copy of the GNU General Public License along with
 ## this program; if not, see <http://www.gnu.org/licenses/>.
 
-## col = checker_color (R,C, checker, col)
+## col = checker_color (checker, colors, R,C) - Checkered colors for a RxC-vertex surface
+##
+## Returns checkered colors for each of the (R-1) x (C-1) facets of a RxC-vertex surface.
+##
+## checker : 1 x 2 : If positive: number of squares in checkerboard
+##                   If negative: number of facets in each checkerboard square
+## 
+## colors  : can be
+##           3 x 2 : The two colors of the checkerboard
+##           1 x 2 : The two intensities of the checkerboard (colors are grey)
+##           3 x 1 : The color of non-black squares of the checkerboard (or non-white, if 
+##                   colors(:) all 0).
+##
+## R, C    : Number of nodes
+## 
+## col     : 3 x (R-1)*(C-1)
 
 function col = checker_color (checker, col, R,C)
 
+if nargin != 4
+  help checker_color
+  error("Wrong arguments");
+endif
+
 if length (checker) == 1, checker = [checker, checker]; end
 
 if checker(1) > 0, checker(1) = - (C-1)/checker(1); end
@@ -30,7 +50,7 @@
 				# Keep at most 1st 2 colors of col for the
 				# checker
 if prod (size (col)) == 2,
-  col = [1;1;1]*col;
+  col = [1;1;1]*col(:)';
 elseif  prod (size (col)) < 6, # Can't be < 3 because of previous code
   col = col(1:3)(:);
   if all (col >= 1-eps), col = [col [0;0;0]];	# Black and White