Add missing utilities

Utilities/L2norm.m

@@ -0,0 +1,5 @@
+function y = L2norm(x,dim)
+if nargin < 2
+    dim = 1;
+end
+y = sqrt(sum(abs(x).^2,dim));

Utilities/filename.m

@@ -0,0 +1,21 @@
+function [file,ext] = filename(str)
+if iscell(str)
+    if nargout > 1
+        for i = 1:length(str)
+            [file{i},ext{i}] = filename(str{i});
+        end
+    else
+        for i = 1:length(str)
+            file{i} = filename(str{i});
+        end
+    end
+    return
+end
+
+[~,file,ext] = fileparts(str);
+
+if nargout < 2
+    if ~isempty(ext)
+        file = [file ext];
+    end
+end

Utilities/moddate.m

@@ -0,0 +1,13 @@
+function datenum = moddate(file)
+if iscell(file)
+    for i = 1:length(file)
+        datenum(i) = moddate(file{i});
+    end
+    return
+end
+path = fileparts(file);
+if isempty(path)
+    file = which(file);
+end
+d = dir(file);
+datenum = d.datenum;

Utilities/normalise.m

@@ -0,0 +1,5 @@
+function y = normalise(x,dim)
+if nargin < 2
+    dim = 1;
+end
+y = x ./L2norm(x,dim);