Merge pull request #293

Image refactor

pyobs/images/image.py

@@ -88,15 +88,8 @@ def from_file(cls, filename: str) -> Image:
             New image.
         """
 
-        # open file
-        data = fits.open(filename, memmap=False, lazy_load_hdus=False)
-
-        # load image
-        image = cls._from_hdu_list(data)
-
-        # close file
-        data.close()
-        return image
+        with fits.open(filename, memmap=False, lazy_load_hdus=False) as data:
+            return cls._from_hdu_list(data)
 
     @classmethod
     def from_ccddata(cls, data: CCDData) -> Image:
@@ -113,7 +106,7 @@ def from_ccddata(cls, data: CCDData) -> Image:
         image = Image(
             data=data.data.astype(np.float32),
             header=data.header,
-            mask=None if data.mask is None else data.mask,
+            mask=data.mask,
             uncertainty=None if data.uncertainty is None else data.uncertainty.array.astype(np.float32),
         )
         return image
@@ -135,10 +128,8 @@ def _from_hdu_list(cls, data: fits.HDUList) -> "Image":
         # find HDU with image data
         for hdu in data:
             if (
-                isinstance(hdu, fits.PrimaryHDU)
-                and hdu.header["NAXIS"] > 0
-                or isinstance(hdu, fits.ImageHDU)
-                and hdu.name == "SCI"
+                isinstance(hdu, fits.PrimaryHDU) and hdu.header["NAXIS"] > 0
+                or isinstance(hdu, fits.ImageHDU) and hdu.name == "SCI"
                 or isinstance(hdu, fits.CompImageHDU)
             ):
                 # found image HDU
@@ -173,7 +164,10 @@ def _from_hdu_list(cls, data: fits.HDUList) -> "Image":
     @property
     def unit(self) -> str:
         """Returns units of pixels in image."""
-        return str(self.header["BUNIT"]).lower() if "BUNIT" in self.header else "adu"
+        if "BUNIT" in self.header:
+            return str(self.header["BUNIT"]).lower()
+        else:
+            return "adu"
 
     def __deepcopy__(self) -> Image:
         """Returns a shallow copy of this image."""
@@ -191,7 +185,7 @@ def copy(self) -> Image:
             meta=self.meta,
         )
 
-    def __truediv__(self, other: "Image") -> "Image":
+    def __truediv__(self, other: Image) -> Image:
         """Divides this image by other."""
         img = self.copy()
         if img.data is None or other.data is None:
@@ -251,8 +245,8 @@ def write_catalog(self, f: Any, *args: Any, **kwargs: Any) -> None:
         if self.catalog is None:
             return
 
-        # create HDU and write it
-        table_to_hdu(self.catalog).writeto(f, *args, **kwargs)
+        hdu = table_to_hdu(self.catalog)
+        hdu.writeto(f, *args, **kwargs)
 
     def to_ccddata(self) -> CCDData:
         """Convert Image to CCDData"""

pyobs/images/meta/__init__.py

@@ -3,3 +3,4 @@
 from .radecoffsets import RaDecOffsets
 from .skyoffsets import SkyOffsets
 from .onskydistance import OnSkyDistance
+from .exptime import ExpTime

tests/images/meta/test_altazoffsets.py

@@ -0,0 +1,11 @@
+from pyobs.images.meta import AltAzOffsets
+
+
+def test_alt_az_offsets():
+    dalt = 1.0
+    daz = 2.0
+
+    meta = AltAzOffsets(dalt, daz)
+
+    assert meta.dalt == dalt
+    assert meta.daz == daz

tests/images/meta/test_exptime.py

@@ -0,0 +1,8 @@
+from pyobs.images.meta import ExpTime
+
+
+def test_exp_time():
+    exp_time = 1.0
+    meta = ExpTime(exp_time)
+
+    assert meta.exptime == exp_time

tests/images/meta/test_onskydistance.py

@@ -0,0 +1,10 @@
+from astropy.coordinates import Angle
+from pyobs.images.meta import OnSkyDistance
+
+
+def test_onskydistance():
+    distance = Angle(1.0, unit="deg")
+    meta = OnSkyDistance(distance)
+
+    assert meta.distance.unit == distance.unit
+    assert meta.distance.value == distance.value

tests/images/meta/test_pixeloffsets.py

@@ -0,0 +1,11 @@
+from pyobs.images.meta import PixelOffsets
+
+
+def test_pixeloffsets():
+    dx = 1.0
+    dy = 2.0
+
+    meta = PixelOffsets(dx, dy)
+
+    assert meta.dx == dx
+    assert meta.dy == dy

tests/images/meta/test_radecoffsets.py

@@ -0,0 +1,12 @@
+from pyobs.images.meta import RaDecOffsets
+
+
+def test_radecoffsets():
+    dra = 1.0
+    ddec = 2.0
+
+    meta = RaDecOffsets(dra, ddec)
+
+    assert meta.dra == dra
+    assert meta.ddec == ddec
+

tests/images/meta/test_skyoffsets.py

@@ -0,0 +1,86 @@
+import astropy
+
+from pyobs.images.meta import SkyOffsets
+from astropy.coordinates import SkyCoord, BaseCoordinateFrame
+
+
+def test_init():
+    coord0 = SkyCoord(ra=0.0, dec=0.0, unit="deg")
+    coord1 = SkyCoord(ra=1.0, dec=1.0, unit="deg")
+
+    meta = SkyOffsets(coord0, coord1)
+
+    assert meta.coord0.ra.deg == coord0.ra.deg
+    assert meta.coord0.dec.deg == coord0.dec.deg
+
+    assert meta.coord1.ra.deg == coord1.ra.deg
+    assert meta.coord1.dec.deg == coord1.dec.deg
+
+
+def test_to_frame_non_value():
+    coord0 = SkyCoord(ra=0.0, dec=0.0, unit="deg")
+    coord1 = SkyCoord(ra=1.0, dec=1.0, unit="deg")
+
+    meta = SkyOffsets(coord0, coord1)
+
+    framed_coord0, framed_coord1 = meta._to_frame()
+
+    assert framed_coord0.ra.deg == coord0.ra.deg
+    assert framed_coord0.dec.deg == coord0.dec.deg
+
+    assert framed_coord1.ra.deg == coord1.ra.deg
+    assert framed_coord1.dec.deg == coord1.dec.deg
+
+
+def test_to_frame_w_value(mocker):
+    """
+    Tests that SkyCoord.transform_to is correctly used
+    """
+    frame = BaseCoordinateFrame()
+
+    coord0 = SkyCoord(ra=0.0, dec=0.0, unit="deg")
+    coord1 = SkyCoord(ra=1.0, dec=1.0, unit="deg")
+    meta = SkyOffsets(coord0, coord1)
+
+    mocker.patch("astropy.coordinates.SkyCoord.transform_to", return_value=0)
+
+    x, y = meta._to_frame(frame)
+
+    astropy.coordinates.SkyCoord.transform_to.assert_called_with(frame)
+
+    assert x == 0
+    assert y == 0
+
+
+def test_separation(mocker):
+    """
+    Tests that _to_frame and separation is correctly used
+    """
+    coord0 = SkyCoord(ra=0.0, dec=0.0, unit="deg")
+    coord1 = SkyCoord(ra=1.0, dec=1.0, unit="deg")
+    meta = SkyOffsets(coord0, coord1)
+
+    mocker.patch.object(meta, "_to_frame", return_value=(coord0, coord1))
+    mocker.patch("astropy.coordinates.SkyCoord.separation", return_value=0)
+
+    assert meta.separation() == 0
+
+    meta._to_frame.assert_called_once_with(None)
+    astropy.coordinates.SkyCoord.separation.assert_called_once_with(coord1)
+
+
+def test_spherical_offsets(mocker):
+    """
+    Tests that _to_frame and spherical_offsets_to is correctly used
+    """
+    coord0 = SkyCoord(ra=0.0, dec=0.0, unit="deg")
+    coord1 = SkyCoord(ra=1.0, dec=1.0, unit="deg")
+    meta = SkyOffsets(coord0, coord1)
+
+    mocker.patch.object(meta, "_to_frame", return_value=(coord0, coord1))
+    mocker.patch("astropy.coordinates.SkyCoord.spherical_offsets_to", return_value=(0, 1))
+
+    assert meta.spherical_offsets() == (0, 1)
+
+    meta._to_frame.assert_called_once_with(None)
+    astropy.coordinates.SkyCoord.spherical_offsets_to.assert_called_once_with(coord1.frame)