Fixes #12: change the IF statement to ensure noise.m wont crash

Author: cabanesc

matlab_codes/update_salinity_mapping.m

@@ -258,30 +258,36 @@ function update_salinity_mapping( pn_float_dir, pn_float_name, po_system_configu
             la_hist_lat   = la_hist_lat  (ii) ;
             la_hist_dates = la_hist_dates(ii) ;
             la_hist_Z = la_hist_Z(ii) ;
-
+            
             % map historical data to float profiles -------------------------
-            %if( length(la_hist_sal)>1 ) % only proceed with mapping if there are more than one data point 
-            %  change config 129 -> at least 5 points are required   
-            if( length(la_hist_sal)>5 ) % only proceed with mapping if there are more than five data point
-
-               % check for outliers
-
-               mean_sal = mean(la_hist_sal);
-               signal_sal = signal( la_hist_sal ) ;
-               bad = find(abs(la_hist_sal-mean_sal)/sqrt(signal_sal) >3);
-               if ~isempty(bad)
-                 la_hist_sal(bad)   = [];
-                 la_hist_long(bad)  = [];
-                 la_hist_lat(bad)   = [];
-                 la_hist_dates(bad) = [];
-                 la_hist_Z(bad)     = [];
-               end
-
-               % use large length scales to map original data
-               % pass NaN for map_age to exclude temporal covariance for large scale mapping
-
-	       noise_sal  = noise( la_hist_sal, la_hist_lat, la_hist_long ) ;
-               signal_sal = signal( la_hist_sal ) ;
+            % check for outliers
+            
+            mean_sal = mean(la_hist_sal);
+            signal_sal = signal( la_hist_sal ) ;
+            
+            if signal_sal>0
+                bad = find(abs(la_hist_sal-mean_sal)/sqrt(signal_sal) >3);
+                
+                if ~isempty(bad)
+                    la_hist_sal(bad)   = [];
+                    la_hist_long(bad)  = [];
+                    la_hist_lat(bad)   = [];
+                    la_hist_dates(bad) = [];
+                    la_hist_Z(bad)     = [];
+                end
+            end
+            
+            
+            % require more than one historical salinity profile with unique position for noise.m; and
+            % require more than five historical salinity profiles to produce realistic mapping error estimates
+            if ( (length(unique(la_hist_long)) > 1 | length(unique(la_hist_lat)) > 1) & length(la_hist_sal) > 5 )
+                
+                
+                % use large length scales to map original data
+                % pass NaN for map_age to exclude temporal covariance for large scale mapping
+                
+                noise_sal  = noise( la_hist_sal, la_hist_lat, la_hist_long ) ;
+                signal_sal = signal( la_hist_sal ) ;
 
                % change config 129