Correction of a small error on the resolution calculation.

HydroGrid.py

@@ -187,10 +187,14 @@ class HydroGrid :
         return indices, polylist
 
     def resolution(self,i,j) :
-        if i+1 >= self.iim or j+1 >= self.jjm :
-            inx=i-1; jnx=j-1
+        if i+1 >= iim :
+            inx=i-1
         else :
-            inx=i+1; jnx=j+1
+            inx=i+1
+        if j+1 >= jjm :
+            jnx=j-1
+        else :
+            jnx=j+1
         dlon = np.radians(np.abs(self.lon[j,i]-self.lon[j,inx]))
         alon = np.cos(np.radians(self.lat[j,i]))**2*(np.sin(dlon/2))**2
         clon = 2*np.arctan2(np.sqrt(alon), np.sqrt(1-alon))