maint: use rows() and columns() to clarify m-files. * gradient.m, interp1q.m, rat.m, tsearchn.m, image.m, imwrite.m, area.m, contourc.m, hist.m, isocolors.m, isonormals.m, meshz.m, print.m, __bar__.m, __go_draw_axes__.m, __interp_cube__.m, __marching_cube__.m, __patch__.m, __print_parse_opts__.m, __quiver__.m, rose.m, shrinkfaces.m, stairs.m, surfnorm.m, tetramesh.m, text.m, deconv.m, spline.m, intersect.m, setdiff.m, setxor.m, union.m, periodogram.m, pcg.m, perms.m: Replace size (x,1) with rows (x) and size(x,2) with columns(x).

--- a/scripts/plot/private/__interp_cube__.m
+++ b/scripts/plot/private/__interp_cube__.m
@@ -39,7 +39,7 @@
   if (size (val) != [length(x), length(y), length(z)])
     error ("__interp_cube__: VAL has wrong dimensions");
   endif
-  if (size (v, 2) != 3)
+  if (columns (v) != 3)
     error ( "v has to be N*3 matrix");
   endif
   if (!ischar (req))