Add support for parallel execution of the vertical sigma layer interpolations....

Add support for parallel execution of the vertical sigma layer interpolations. In addition to this function being launched in parallel, the subfunction grid_vert_interp.m is also parallelised. Although, now that I think about it, that might mean the two functions are competing for the workers in the pool and thus might be suboptimal. I will have to run some tests to see if that is the case

fvcom_prepro/interp_POLCOMS2FVCOM.m

@@ -40,6 +40,8 @@ function Mobj = interp_POLCOMS2FVCOM(Mobj, ts, start_date, varlist)
 %
 % Revision history
 %   2013-02-08 First version.
+%   2013-05-16 Add support for parallel for-loops (not mandatory, but
+%   enabled if the Parallel Computing Toolbox is available).
 %
 %==========================================================================
 
@@ -47,8 +49,19 @@ subname = 'interp_POLCOMS2FVCOM';
 
 global ftbverbose;
 if ftbverbose
-    fprintf('\n')
-    fprintf(['begin : ' subname '\n'])
+    fprintf('\nbegin : %s\n', subname)
+end
+
+% Run jobs on multiple workers if we have that functionality. Not sure if
+% it's necessary, but check we have the Parallel Toolbox first.
+wasOpened = false;
+if license('test', 'Distrib_Computing_Toolbox')
+    % We have the Parallel Computing Toolbox, so launch a bunch of workers.
+    if matlabpool('size') == 0
+        % Force pool to be local in case we have remote pools available.
+        matlabpool open local
+        wasOpened = true;
+    end
 end
 
 %--------------------------------------------------------------------------
@@ -123,8 +136,10 @@ end
 
 fvtemp = nan(fn, fz);
 fvsalt = nan(fn, fz);
-for zi = 1:fz
-    % Set up the interpolation object.
+
+tic
+parfor zi = 1:fz
+    % Set up the interpolation objects.
     ft = TriScatteredInterp(lon(:), lat(:), reshape(pc.tempz(:, :, zi), [], 1), 'natural');
     fs = TriScatteredInterp(lon(:), lat(:), reshape(pc.salz(:, :, zi), [], 1), 'natural');
     % Interpolate temperature and salinity onto the unstructured grid.
@@ -146,7 +161,10 @@ end
 fvidx = 1:fn;
 fvnanidx = fvidx(isnan(fvtemp(:, 1)));
 fvfinidx = fvidx(~isnan(fvtemp(:, 1)));
-for ni = 1:length(fvnanidx);
+
+% Can't parallelise this one (easily). It shouldn't be a big part of the
+% run time if your source data covers the domain sufficiently.
+for ni = 1:length(fvnanidx)
     % Current position
     xx = Mobj.lon(fvnanidx(ni));
     yy = Mobj.lat(fvnanidx(ni));
@@ -160,11 +178,17 @@ end
 
 if ftbverbose
     fprintf('done.\n') 
+    toc
 end
 
 Mobj.restart.temp = fvtemp;
 Mobj.restart.salinity = fvsalt;
 
+% Close the MATLAB pool if we opened it.
+if wasOpened
+    matlabpool close
+end
+
 if ftbverbose
-    fprintf(['end   : ' subname '\n'])
+    fprintf('end   : %s\n', subname)
 end