Add .to_spec() and .from_spec() functions for Focus and Gridgen class…

…es. Additonal tests are added

pygridgen/grid.py

@@ -195,6 +195,17 @@ def __call__(self, x, y):
             x, y = focuspoint(x, y)
         return x, y
 
+    def to_spec(self):
+        output_spec = []
+        for focuspoint in self._focuspoints:
+            output_spec.append(focuspoint.to_dict())
+        return output_spec
+
+    def from_spec(foci):
+        f = Focus()
+        for focuspoint in foci:            
+            f.add_focus(**focuspoint)
+        return f
 
 class CGrid(object):
     """
@@ -972,6 +983,17 @@ def generate_grid(self):
 
         super(Gridgen, self).__init__(x, y)
 
+    def to_spec(self):
+        output_dict = {'xbry':self.xbry, 'ybry':self.ybry, 
+                       'beta':self.beta, 'shape':self.shape,
+                       'focus':self.focus}
+
+        return output_dict
+
+    def from_spec(attributes):
+        # print(attributes)
+        g = Gridgen(**attributes)
+        return g
 
 def rho_to_vert(xr, yr, pm, pn, ang):  # pragma: no cover
     """ Possibly converts centroids to nodes """

pygridgen/tests/test_focus.py

@@ -156,3 +156,24 @@ def test_focuspoint_to_dict():
     fp2 = pygridgen.grid._FocusPoint(**fp.to_dict())
     assert fp.to_dict() == {'pos': 0.25, 'axis': 'x', 'factor': 4, 'extent': 0.5}
     assert fp.to_dict() == fp2.to_dict()
+
+def test_focus_to_from_spec():
+    fpx = pygridgen.grid._FocusPoint(0.25, 'x', 4, 0.5)
+    fpy = pygridgen.grid._FocusPoint(0.33, 'y', 0.1, 0.2)
+    f1 = pygridgen.grid.Focus(fpx, fpy)
+
+    ## Check that the spec dictionary returns desired results
+    assert f1.to_spec() == [
+        {'pos': 0.25, 'axis': 'x', 'factor': 4, 'extent': 0.5},
+        {'pos': 0.33, 'axis': 'y', 'factor': 0.1, 'extent': 0.2}
+    ]
+
+    f2 = pygridgen.grid.Focus.from_spec(f1.to_spec())
+
+    ## Check that the spec dictionary returns desired results of the orignal 
+    ## focus and the focus generated from .to_spec()
+    ## First check the keys are in order and then check the values
+    for dict1, dict2 in zip(f1.to_spec(), f2.to_spec()):
+        numpy.testing.assert_equal(dict1.keys(), dict2.keys())
+        for value1, value2 in zip(dict1.values(), dict2.values()):
+            assert value1==value2

pygridgen/tests/test_grid.py

@@ -589,3 +589,15 @@ def test_mask_poylgon(grid_and_knowns):
         ])
         grid.mask_polygon(island)
         nptest.assert_array_almost_equal(grid.mask_rho, known_mask_rho)
+
+def test_gridgen_to_from_spec():
+    focus = pygridgen.Focus()
+    focus.add_focus(0.50, 'y', factor=5, extent=0.25)
+    focus.add_focus(0.50, 'x', factor=5, extent=0.25)
+
+    grid1 = pygridgen.Gridgen(x, y, beta, shape=(20, 10), focus=focus)
+    grid2 = pygridgen.grid.Gridgen.from_spec((grid1.to_spec()))
+
+    # testing - using almost equal due to rounding issues with floats
+    numpy.testing.assert_array_almost_equal(grid1.x, grid2.x)
+    numpy.testing.assert_array_almost_equal(grid1.y, grid2.y)