Fix input argument checking to allow single monitoring microphone and source calculations

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

@@ -3,7 +3,7 @@
 % Author: Achilles Kappis
 % e-mail: axilleaz@protonmail.com
 %
-% Date: 13/09/2024 (DD/MM/YYYY)
+% Date: 14/09/2024 (DD/MM/YYYY)
 %
 % Copyright: MIT
 % --------------------------------------------------
@@ -73,8 +73,8 @@ function [estPerMic, est, err, estMean, errMean] = obsFiltEstTD(m, O, e)
     validateattributes(O, "numeric", {'real', 'nonnan', 'nonempty', 'finite'}, mfilename, "Observation filters", 2);
 
     % Check for observation filter size
-    if ismatrix(O) || ndims(O) > 4
-        error("Observation filter must be either a three- or four-dimensional array. See documentation (at the top of the function file) for more information.");
+    if ndims(O) > 4
+        error("Observation filter array cannot have more than four dimensions. See documentation (at the top of the function file) for more information.");
     elseif size(O, 4) ~= size(m, 3) && size(O, 4) ~= 1
         error("The number of observation filter sets must be either equal to the trials/sound field realisations, or 1.")
     end