Fix dependencies. Simplify tests. Reduce data file size. Add a new unit test. (#166)

Remove unused data files. Simplify tests. Add new tests

Author: mcara

drizzle/tests/data/input1.fits

@@ -0,0 +1,52 @@
+import os
+
+import numpy as np
+
+from astropy import wcs
+from astropy.io import fits
+
+__all__ = ["wcs_from_file"]
+
+TEST_DIR = os.path.abspath(os.path.dirname(__file__))
+DATA_DIR = os.path.join(TEST_DIR, 'data')
+
+
+def wcs_from_file(filename, ext=None, return_data=False, crpix_shift=None):
+    """
+    Read the WCS from a ".fits" file.
+    """
+    full_file_name = os.path.join(DATA_DIR, filename)
+    path = os.path.join(DATA_DIR, full_file_name)
+    with fits.open(path) as hdu:
+        if ext is None:
+            for k, u in enumerate(hdu):
+                if "CTYPE1" in u.header:
+                    ext = k
+                    break
+
+        hdr = hdu[ext].header
+        naxis1 = hdr.get("WCSNAX1", hdr.get("NAXIS1"))
+        naxis2 = hdr.get("WCSNAX2", hdr.get("NAXIS2"))
+        if naxis1 is not None and naxis2 is not None:
+            shape = (naxis2, naxis1)
+            if hdu[ext].data is None:
+                hdu[ext].data = np.zeros(shape, dtype=np.float32)
+        else:
+            shape = None
+
+        if crpix_shift is not None and "CRPIX1" in hdr:
+            hdr["CRPIX1"] += crpix_shift[0]
+            hdr["CRPIX2"] += crpix_shift[1]
+
+        result = wcs.WCS(hdr, hdu)
+        result.array_shape = shape
+
+        if return_data:
+            result = (result, )
+            if not isinstance(return_data, (list, tuple)):
+                return_data = [ext]
+            for ext in return_data:
+                data = (hdu[ext].data, )
+                result = result + data
+
+    return result