# HG changeset patch
# User jwe
# Date 1083875789 0
# Node ID e7da90a1cc114f6c63eb877ea37c72bafc6879da
# Parent  658aad1c1b05731c987839b3f7568752e95eb14a
[project @ 2004-05-06 20:36:29 by jwe]

diff --git a/scripts/ChangeLog b/scripts/ChangeLog
--- a/scripts/ChangeLog
+++ b/scripts/ChangeLog
@@ -1,3 +1,17 @@
+2004-05-06  David Bateman  <dbateman@free.fr>
+
+	* general/issquare.m: Fail if ndim(x) > 2.
+
+	* linear-algebra/norm.m, linear-algebra/norm.m: Fail if ndim(x) > 2.
+
+	* linear-alegbra/cross.m, linear-algebra/dot.m: Allow matrix and
+	N-d array arguments.  Add optional dim argument to define
+	dimension along which to operate.
+
+	* linear-algebra/dmult.m: Allow N-d arrays.
+
+	* linear-algebra/vec.m: Use v(:) and not reshape.
+
 2004-04-29  David Bateman  <dbateman@free.fr>
 
 	* statistics/base/ranks.m, statistics/base/run_count.m,
diff --git a/scripts/general/issquare.m b/scripts/general/issquare.m
--- a/scripts/general/issquare.m
+++ b/scripts/general/issquare.m
@@ -33,7 +33,7 @@
   retval = 0;
 
   if (nargin == 1)
-    if (ismatrix (x))
+    if (ismatrix (x) && ndims (x) < 3)
       [nr, nc] = size (x);
       if (nr == nc && nr > 0)
         retval = nr;
diff --git a/scripts/linear-algebra/cond.m b/scripts/linear-algebra/cond.m
--- a/scripts/linear-algebra/cond.m
+++ b/scripts/linear-algebra/cond.m
@@ -30,6 +30,10 @@
 function retval = cond (a)
 
   if (nargin == 1)
+    if (ndims (x) > 2)
+      error ("cond: Only valid on 2-D objects")
+    endif
+
     [nr, nc] = size (a);
     if (nr == 0 || nc == 0)
       retval = 0.0;
diff --git a/scripts/linear-algebra/cross.m b/scripts/linear-algebra/cross.m
--- a/scripts/linear-algebra/cross.m
+++ b/scripts/linear-algebra/cross.m
@@ -18,7 +18,7 @@
 ## 02111-1307, USA.
 
 ## -*- texinfo -*-
-## @deftypefn {Function File} {} cross (@var{x}, @var{y})
+## @deftypefn {Function File} {} cross (@var{x}, @var{y}, @var{dim})
 ## Computes the vector cross product of the two 3-dimensional vectors
 ## @var{x} and @var{y}.
 ##
@@ -29,44 +29,62 @@
 ## @end group
 ## @end example
 ##
-## If @var{x} and @var{y} are two - dimensional matrices the
-## cross product is applied along the first dimension with 3 elements.
-##
+## If @var{x} and @var{y} are matrices, the cross product is applied 
+## along the first dimension with 3 elements. The optional argument 
+## @var{dim} is used to force the cross product to be calculated along
+## the dimension defiend by @var{dim}.
 ## @end deftypefn
 
 ## Author: Kurt Hornik <Kurt.Hornik@ci.tuwien.ac.at>
 ## Created: 15 October 1994
 ## Adapted-By: jwe
 
-function z = cross (x, y)
+function z = cross (x, y, dim)
 	
-  if (nargin != 2)
-    usage ("cross (x, y)");
+  if (nargin != 2 && nargin != 3)
+    usage ("cross (x, y, dim)");
+  endif
+
+  if (ndims (x) < 3 && ndims (y) < 3 && nargin < 3)
+    ## XXX COMPATIBILITY XXX opposite behaviour for cross(row,col)
+    ## Swap x and y in the assignments below to get the matlab behaviour.
+    ## Better yet, fix the calling code so that it uses conformant vectors.
+    if (columns (x) == 1 && rows (y) == 1)
+      warning ("cross: taking cross product of column by row");
+      y = y.';
+    elseif (rows (x) == 1 && columns (y) == 1)
+      warning ("cross: taking cross product of row by column");
+      x = x.';
+    endif
   endif
 
-  ## XXX COMPATIBILITY XXX opposite behaviour for cross(row,col)
-  ## Swap x and y in the assignments below to get the matlab behaviour.
-  ## Better yet, fix the calling code so that it uses conformant vectors.
-  if (columns(x) == 1 && rows(y) == 1)
-    warning ("cross: taking cross product of column by row");
-    y = y.';
-  elseif (rows(x) == 1 && columns(y) == 1)
-    warning ("cross: taking cross product of row by column");
-    x = x.';
+  if (nargin == 2)
+     dim = min (find (size (x) == 3));
+     if (isempty (dim)) 
+       error ("cross: must have at least one dimension with 3 elements");
+     endif
+   else
+     if (size (x) != 3)
+       error ("cross: dimension dim must have 3 elements");
+     endif
   endif
 
-  if (size(x) == size(y))
-    if (rows(x) == 3)
-      z = [ ( x (2,:) .* y (3,:) - x (3,:) .* y (2,:) ) ;
-            ( x (3,:) .* y (1,:) - x (1,:) .* y (3,:) ) ;
-            ( x (1,:) .* y (2,:) - x (2,:) .* y (1,:) ) ];
-    elseif (columns(x) == 3)
-      z = [ ( x (:,2) .* y (:,3) - x (:,3) .* y (:,2) ) , \
-            ( x (:,3) .* y (:,1) - x (:,1) .* y (:,3) ) , \
-            ( x (:,1) .* y (:,2) - x (:,2) .* y (:,1) ) ];
-    else
-      error ("cross: x,y must have dimension nx3 or 3xn");
-    endif
+  nd = ndims (x);
+  sz = size (x);
+  idx1 = cell ();
+  for i = 1:nd
+    idx1{i} = 1:sz(i);
+  endfor
+  idx2 = idx3 = idx1;
+  idx1(dim) = 1;
+  idx2(dim) = 2;
+  idx3(dim) = 3;
+
+  if (size (x) == size (y))
+    z = cat (dim, 
+	     (x(idx2{:}) .* y(idx3{:}) - x(idx3{:}) .* y(idx2{:})),
+             (x(idx3{:}) .* y(idx1{:}) - x(idx1{:}) .* y(idx3{:})),
+             (x(idx1{:}) .* y(idx2{:}) - x(idx2{:}) .* y(idx1{:})));
   else
     error ("cross: x and y must have the same dimensions");
   endif
diff --git a/scripts/linear-algebra/dmult.m b/scripts/linear-algebra/dmult.m
--- a/scripts/linear-algebra/dmult.m
+++ b/scripts/linear-algebra/dmult.m
@@ -31,12 +31,11 @@
   if (nargin != 2)
     usage ("dmult (a, B)");
   endif
-
-  s = size (a);
-  if ((min (s) > 1) || (max (s) != rows (B)))
+ if (! isvector (a))
     error ("dmult: a must be a vector of length rows (B)");
   endif
-
-  M = (reshape (a, max (s), 1) * ones (1, columns (B))) .* B;
-
+  a = a(:);
+  sb = size (B);
+  sb(1) = 1;
+  M = repmat (a(:), sb) .* B;
 endfunction
diff --git a/scripts/linear-algebra/dot.m b/scripts/linear-algebra/dot.m
--- a/scripts/linear-algebra/dot.m
+++ b/scripts/linear-algebra/dot.m
@@ -18,36 +18,37 @@
 ## 02111-1307, USA.
 
 ## -*- texinfo -*-
-## @deftypefn {Function File} {} dot (@var{x}, @var{y})
-## Computes the dot product of two vectors.
+## @deftypefn {Function File} {} dot (@var{x}, @var{y}, @var{dim})
+## Computes the dot product of two vectors. If @var{x} and @var{y}
+## are matrices, calculate the dot-product along the first 
+## non-singleton dimension. If the optional argument @var{dim} is
+## given, calculate the dot-product along this dimension.
 ## @end deftypefn
 
 ## Author: jwe
 
-function z = dot (x, y)
+function z = dot (x, y, dim)
 
-  if (nargin != 2)
-    usage ("dot (x, y)");
+  if (nargin != 2 && nargin != 3)
+    usage ("dot (x, y, dim)");
   endif
 
-  if (isvector (x) && isvector (y) && length (x) == length (y))
-    [x_nr, x_nc] = size (x);
-    [y_nr, y_nc] = size (y);
-    if (x_nr == 1)
-      if (y_nr == 1)
-        z = x * y.';
-      else
-        z = x * y;
-      endif
-    else
-      if (y_nr == 1)
-        z = y * x;
-      else
-        z = y.' * x;
-      endif
+  if (nargin < 3)
+    if isvector (x)
+      x = x(:);
+    endif
+    if isvector (y)
+      y = y(:);
     endif
+    if (size (x) != size (y))
+      error ("dot: sizes of arguments must match")
+    endif
+    z = sum(x .* y);
   else
-    error ("dot: both arguments must be vectors of the same length");
+    if (size (x) != size (y))
+      error ("dot: sizes of arguments must match")
+    endif
+    z = sum(x .* y, dim);
   endif
 
 endfunction
diff --git a/scripts/linear-algebra/norm.m b/scripts/linear-algebra/norm.m
--- a/scripts/linear-algebra/norm.m
+++ b/scripts/linear-algebra/norm.m
@@ -68,6 +68,10 @@
     return;
   endif
 
+  if (ndims (x) > 2)
+    error ("norm: Only valid on 2-D objects")
+  endif
+
   ## Do we have a vector or matrix as the first argument?
 
   if (rows (x) == 1 || columns (x) == 1)
diff --git a/scripts/linear-algebra/vec.m b/scripts/linear-algebra/vec.m
--- a/scripts/linear-algebra/vec.m
+++ b/scripts/linear-algebra/vec.m
@@ -36,6 +36,6 @@
     usage ("vec (x)");
   endif
 
-  v = reshape (x, prod (size (x)), 1);
+  v = x(:);
 
 endfunction