Fix bug throwing error when providing a 3D array as input

Utilities/Generic/MATLAB/Functions/diagMetric.m

@@ -69,7 +69,7 @@ function diagonality = diagMetric(mat, matNorm, normalise)
     % Validate input arguments
     % ====================================================
     % Validate mandatory arguments
-    validateattributes(mat, "numeric", {'3d', 'square', 'nonempty'}, mfilename, "Matrices to be checked for diagonality", 1);
+    validateattributes(mat, "numeric", {'3d', 'nonempty', 'size', [NaN, size(mat, 1), NaN]}, mfilename, "Matrices to be checked for diagonality", 1);
 
     % Validate optional arguments
     if nargin > 1 && ~isempty(matNorm)