Maths: fixed reshape error in matrix multiplication

Signed-off-by: Nicola Vigano <nicola.vigano@esrf.fr>

zUtil_Maths/gtMathsMatrixProduct.m

@@ -2,10 +2,23 @@ function C = gtMathsMatrixProduct(A, B)
     [size_A(1), size_A(2), size_A(3)] = size(A);
     [size_B(1), size_B(2), size_B(3)] = size(B);
 
+    if (size_A(3) ~= size_B(3))
+        if (all([size_A(3), size_B(3)] ~= 1))
+            error('gtMathsMatrixProduct:wrong_argument', ...
+                'The matrix stacks should have either the same number of matrices, or one should be one')
+        elseif (size_A(3) == 1)
+            num_out = size_B(3);
+        else
+            num_out = size_A(3);
+        end
+    else
+        num_out = size_A(3);
+    end
+
     A = reshape(A, size_A(1), size_A(2), 1, size_A(3));
     B = reshape(B, 1, size_B(1), size_B(2), size_B(3));
 
     C = bsxfun(@times, A, B);
     C = sum(C, 2);
-    C = reshape(C, size_A(1), size_B(2), size_A(3));
+    C = reshape(C, size_A(1), size_B(2), num_out);
 end