Update obsFilt function to allow a matrix of regularisation factors to be provided

Virtual Sensing/Remote Microphone Technique/MATLAB/Functions/obsFilt.m

@@ -3,7 +3,7 @@
 % Author: Achilles Kappis
 % e-mail: axilleaz@protonmail.com
 %
-% Date: 13/02/2025 (DD/MM/YYYY)
+% Date: 14/02/2025 (DD/MM/YYYY)
 %
 % Copyright: MIT
 % --------------------------------------------------
@@ -31,9 +31,10 @@
 %                               inversion of the cross-spectra of the
 %                               monitoring microphones. Can be a vector
 %                               with number of elements equal to K (number
-%                               of monitoring microphones) or a scalar
+%                               of monitoring microphones), a scalar
 %                               which will result in the same
-%                               regularisation factor for all microphones.
+%                               regularisation factor for all microphones,
+%                               or a square matrix with dimensions KxK.
 %                               [Default: 0]
 % 
 % snrVal [numeric] (Optional): This is the Root-Mean-Square (RMS)
@@ -105,11 +106,15 @@ function [oOpt, Sme, Smm, condNum] = obsFilt(Pe, Pm, Svv, regFacs, snrVal)
     end
 
     if nargin > 3 && ~isempty(regFacs)
-        validateattributes(regFacs, "numeric", {'vector', 'nonnegative', 'nonnan', 'nonempty', 'finite'}, mfilename, "Regularisation factors", 4);
+        validateattributes(regFacs, "numeric", {'2d', 'nonnan', 'nonempty', 'finite'}, mfilename, "Regularisation factors", 4);
 
         % Make sure regFacs has correct dimensions
-        if ~isscalar(regFacs) && numel(regFacs) ~= size(Pm, 1)
-            error("Regularisation factors must be either a scalar or its length must match the number of monitoring microphones.");
+        if ~isscalar(regFacs)
+            if isvector(regFacs) && numel(regFacs) ~= size(Pm, 1)
+                error("If the regularisation factors are given as a vector the number of elements must match the number of monitoring microphones.");
+            elseif ismatrix(regFacs) && ~isequal(size(regFacs), ones(1, 2) .* size(Pm, 1))
+                error("If the regularisation factors are given as a matrix, it must be a square matrix with each dimension equal to the number of monitoring microphones.");
+            end
         end
     else
         regFacs = 0;
@@ -143,8 +148,10 @@ function [oOpt, Sme, Smm, condNum] = obsFilt(Pe, Pm, Svv, regFacs, snrVal)
     % Regularisation matrix
     if isscalar(regFacs)
         regMat = eye(size(Smm)) .* regFacs;
-    else
+    elseif isvector(regFacs)
         regMat = diag(regFacs);
+    else
+        regMat = regFacs;
     end
 
     % Signal-to-Noise Ratio at the monitoring microphones