Fix some remaining FORTRAN code (do loop and float function) to MATLAB. Also...

Fix some remaining FORTRAN code (do loop and float function) to MATLAB. Also add a function description to match the format of the other tools in the toolbox. Also reformat the code to MATLAB standard format (indentation etc.).

utilities/sigma_geo.m

-function dist = sigma_geo(nlev,p_sigma)
+function dist = sigma_geo(nlev, p_sigma)
+% Generate a geometric sigma coordinate distribution.
+%
+% Mobj = sigma_gen(nlev, p_sigma)
+%
+% DESCRIPTION:
+%   Generate a geometric vertical sigma coordinate distribution.
+%
+% INPUT:
+%   nlev:       Number of sigma levels (layers + 1)
+%   p_sigma:    1 for uniform sigma layers, 2 for parabolic function. See
+%               page 308-309 in the FVCOM manual for examples.
+%
+% OUTPUT:
+%   dist:       Geometric vertical sigma coordinate distribution.
+%
+% EXAMPLE USAGE:
+%   Mobj = read_sigma(21, 2.0)
+%
+% Author(s):
+%   Geoff Cowles (University of Massachusetts Dartmouth)
+%   Pierre Cazenave (Plymouth Marine Laboratory)
+%
+% Revision history
+%   2013-04-23 Added help on the function and reformatted the code to
+%   remove to FORTRAN in the else block.
+
+dist = nan(1, nlev);
 
 kb = nlev;
-if(p_sigma ==1)
-  for k=1:nlev
-    dist(k) = -((k-1)/float(kb-1))^p_sigma;
-  end;
-else
-  for k=1:(kb+1)/2
-    dist(k) = -((k-1)/float((kb+1)/2-1))^p_sigma/2;
-  end;
-  do k=(kb+1)/2+1:kb   
-    dist(k) = ((kb-k)/float((kb+1)/2-1))^p_sigma/2-1.0;
-  end;
-end;
 
+if p_sigma == 1
+    for k = 1:nlev
+        dist(k) = -((k-1)/(kb-1))^p_sigma;
+    end
+else
+    for k = 1:(kb+1)/2
+        dist(k) = -((k-1)/((kb+1)/2-1))^p_sigma/2;
+    end
+    for k = (kb+1)/2+1:kb
+        dist(k) = ((kb-k)/((kb+1)/2-1))^p_sigma/2-1.0;
+    end
+end