Allow metadata to be passed when passing transform instead of WCS to …

…get_coords_overlay

wcsaxes/coordinate_helpers.py

@@ -29,11 +29,12 @@ def wrap_angle_at(values, coord_wrap):
 
 class CoordinateHelper(object):
 
-    def __init__(self, parent_axes=None, transform=None, coord_index=None,
+    def __init__(self, parent_axes=None, parent_map=None, transform=None, coord_index=None,
                  coord_type='scalar',coord_unit=None, coord_wrap=None, frame=None):
 
         # Keep a reference to the parent axes and the transform
         self.parent_axes = parent_axes
+        self.parent_map = parent_map
         self.transform = transform
         self.coord_index = coord_index
         self.coord_type = coord_type
@@ -336,7 +337,7 @@ def _update_ticks(self, renderer):
         # to determine the rotations.
 
         # Find the range of coordinates in all directions
-        coord_range = self.parent_axes.get_coord_range(self.transform)
+        coord_range = self.parent_map.get_coord_range()
 
         # First find the ticks we want to show
         tick_world_coordinates, spacing = self._formatter_locator.locator(*coord_range[self.coord_index])
@@ -480,7 +481,7 @@ def _update_grid_lines(self):
         # the value in the slice). Here we basically assume that if the WCS
         # had a third axis, it has been abstracted away in the transformation.
 
-        coord_range = self.parent_axes.get_coord_range(self.transform)
+        coord_range = self.parent_map.get_coord_range()
 
         tick_world_coordinates, spacing = self._formatter_locator.locator(*coord_range[self.coord_index])
         tick_world_coordinates_values = tick_world_coordinates.value
@@ -509,7 +510,7 @@ def _update_grid_contour(self):
 
         X, Y, field = self.transform.get_coord_slices(xmin, xmax, ymin, ymax, 200, 200)
 
-        coord_range = self.parent_axes.get_coord_range(self.transform)
+        coord_range = self.parent_map.get_coord_range()
 
         tick_world_coordinates, spacing = self._formatter_locator.locator(*coord_range[self.coord_index])
 

wcsaxes/coordinates_map.py

@@ -2,13 +2,14 @@
 from .transforms import WCSPixel2WorldTransform
 from .utils import coord_type_from_ctype
 from .frame import RectangularFrame
+from .coordinate_range import find_coordinate_range
 
 from . import six
 
 
 class CoordinatesMap(object):
 
-    def __init__(self, axes, wcs, transform=None, slice=None):
+    def __init__(self, axes, wcs, transform=None, coord_meta=None, slice=None):
 
         # Keep track of parent axes and WCS
         self._axes = axes
@@ -28,9 +29,24 @@ def __init__(self, axes, wcs, transform=None, slice=None):
 
         for coord_index in range(self._wcs.wcs.naxis):
 
-            coord_type, coord_wrap = coord_type_from_ctype(wcs.wcs.ctype[coord_index])
-            coord_unit = wcs.wcs.cunit[coord_index]
+            # Extract coordinate metadata from WCS object or transform
+            if transform is None:
+                coord_type, coord_wrap = coord_type_from_ctype(wcs.wcs.ctype[coord_index])
+                coord_unit = wcs.wcs.cunit[coord_index]
+                name = self._wcs.wcs.ctype[coord_index][:4].replace('-', '')
+            elif coord_meta is not None:
+                try:
+                    coord_type = coord_meta['type'][coord_index]
+                    coord_wrap = coord_meta['wrap'][coord_index]
+                    coord_unit = coord_meta['unit'][coord_index]
+                    name = coord_meta['name'][coord_index]
+                except IndexError:
+                    raise ValueError("coord_meta items should have a length of {0}".format(len(self._wcs.wcs.naxis)))
+            else:
+                raise ValueError("coord_meta should be set")
+
             self._coords.append(CoordinateHelper(parent_axes=axes,
+                                                 parent_map=self,
                                                  transform=self._transform,
                                                  coord_index=coord_index,
                                                  coord_type=coord_type,
@@ -40,7 +56,6 @@ def __init__(self, axes, wcs, transform=None, slice=None):
 
 
             # Set up aliases for coordinates
-            name = self._wcs.wcs.ctype[coord_index][:4].replace('-', '')
             self._aliases[name.lower()] = coord_index
 
     def __getitem__(self, item):
@@ -84,3 +99,10 @@ def grid(self, draw_grid=True, grid_type='lines', **kwargs):
         """
         for coord in self:
             coord.grid(draw_grid=draw_grid, grid_type=grid_type, **kwargs)
+
+    def get_coord_range(self):
+        xmin, xmax = self._axes.get_xlim()
+        ymin, ymax = self._axes.get_ylim()
+        return find_coordinate_range(self._transform,
+                                     [xmin, xmax, ymin, ymax],
+                                     [coord.coord_type for coord in self])

wcsaxes/wcsaxes.py

@@ -72,13 +72,6 @@ def reset_wcs(self, wcs, slices=None):
                 self.coords[coord_index].set_ticklabel_position('')
                 self.coords[coord_index].set_ticks_position('')
 
-    def get_coord_range(self, transform):
-        xmin, xmax = self.get_xlim()
-        ymin, ymax = self.get_ylim()
-        return find_coordinate_range(transform,
-                                     [xmin, xmax, ymin, ymax],
-                                     [coord.coord_type for coord in self.coords])
-
     def draw(self, renderer, inframe=False):
 
         super(WCSAxes, self).draw(renderer, inframe)
@@ -113,15 +106,15 @@ def get_xlabel(self):
     def get_ylabel(self):
         return self.coords[1].get_axislabel()
 
-    def get_coords_overlay(self, frame, equinox=None, obstime=None):
+    def get_coords_overlay(self, frame, equinox=None, obstime=None, coord_meta=None):
 
         # Here we can't use get_transform because that deals with
         # pixel-to-pixel transformations when passing a WCS object.
         if isinstance(frame, WCS):
-            coords = CoordinatesMap(self, frame)
+            coords = CoordinatesMap(self, frame, coord_meta=coord_meta)
         else:
             transform = self._get_transform_no_transdata(frame, equinox=equinox, obstime=obstime)
-            coords = CoordinatesMap(self, self.wcs, transform=transform)
+            coords = CoordinatesMap(self, self.wcs, transform=transform, coord_meta=coord_meta)
 
         self._all_coords.append(coords)