Improved computation of scaling that works across various projections

Packages/vcs/Lib/vcsvtk/vectorpipeline.py

@@ -41,9 +41,6 @@ def plot(self, data1, data2, tmpl, grid, transform):
         if lonAccesrsor:
             lon = lonAccesrsor[:]
 
-        if None not in (projection, lat, lon):
-            scale = (lat.max() - lat.min()) * (lon.max() - lon.min())
-
         gridGenDict = vcs2vtk.genGridOnPoints(data1, self._gm, deep=False, grid=grid,
                                               geo=transform, data2=data2)
 
@@ -68,9 +65,20 @@ def plot(self, data1, data2, tmpl, grid, transform):
                                   gridGenDict['ym'], gridGenDict['yM']])
             dimMin = [0, 0, 0]
             dimMax = [0, 0, 0]
+
             newv.GetTupleValue(0, dimMin)
             newv.GetTupleValue(1, dimMax)
-            scale = (dimMax[1] - dimMin[1]) * (dimMax[0] - dimMin[0])/scale
+
+            maxDimX = max(dimMin[0], dimMax[0])
+            maxDimY = max(dimMin[1], dimMax[1])
+
+            if lat.max() != 0.0:
+                scale = abs((maxDimY / lat.max()))
+
+            if lon.max() != 0.0:
+                temp = abs((maxDimX / lon.max()))
+                if scale < temp:
+                    scale = temp
         else:
             scale = 1.0
 
@@ -121,7 +129,7 @@ def plot(self, data1, data2, tmpl, grid, transform):
 
         # Scale to vector magnitude:
         glyphFilter.SetScaleModeToScaleByVector()
-        glyphFilter.SetScaleFactor(math.sqrt(scale) * 2.0 * self._gm.scale)
+        glyphFilter.SetScaleFactor(scale * 2.0 * self._gm.scale)
 
         # These are some unfortunately named methods. It does *not* clamp the
         # scale range to [min, max], but rather remaps the range