Merge pull request #253 from mwcraig/more-camera-settings

Tidy up Camera-related tests and add a name property

stellarphot/photometry/tests/test_photometry.py

@@ -29,14 +29,28 @@
 
 SHIFT_TOLERANCE = 6
 FWHM_ESTIMATE = 5
+
+# A camera with not unreasonable settings
 FAKE_CAMERA = Camera(
     data_unit=u.adu,
     gain=1.0 * u.electron / u.adu,
+    name="test camera",
     read_noise=0 * u.electron,
     dark_current=0.1 * u.electron / u.second,
     pixel_scale=1 * u.arcsec / u.pixel,
     max_data_value=40000 * u.adu,
 )
+
+# Camera with no read noise or dark currnet
+ZERO_CAMERA = Camera(
+    data_unit=u.adu,
+    gain=1.0 * u.electron / u.adu,
+    name="test camera",
+    read_noise=0 * u.electron,
+    dark_current=0.0 * u.electron / u.second,
+    pixel_scale=1 * u.arcsec / u.pixel,
+    max_data_value=40000 * u.adu,
+)
 FAKE_OBS = EarthLocation(lat=0 * u.deg, lon=0 * u.deg, height=0 * u.m)
 COORDS2USE = "pixel"
 
@@ -57,14 +71,8 @@ def test_calc_noise_source_only(gain, aperture_area):
     expected = np.sqrt(gain * counts)
 
     # Create camera instance
-    camera = Camera(
-        data_unit=u.adu,
-        gain=gain * u.electron / u.adu,
-        read_noise=0 * u.electron,
-        dark_current=0 * u.electron / u.second,
-        pixel_scale=1 * u.arcsec / u.pixel,
-        max_data_value=40000 * u.adu,
-    )
+    camera = ZERO_CAMERA.copy()
+    camera.gain = gain * camera.gain.unit
 
     np.testing.assert_allclose(
         calculate_noise(camera, counts=counts, aperture_area=aperture_area), expected
@@ -80,14 +88,10 @@ def test_calc_noise_dark_only(gain, aperture_area):
     exposure = 20
 
     # Create camera instance
-    camera = Camera(
-        data_unit=u.adu,
-        gain=gain * u.electron / u.adu,
-        read_noise=0 * u.electron,
-        dark_current=dark_current * u.electron / u.second,
-        pixel_scale=1 * u.arcsec / u.pixel,
-        max_data_value=40000 * u.adu,
-    )
+    camera = ZERO_CAMERA.copy()
+    # Set gain and dark current to values for test
+    camera.dark_current = dark_current * camera.dark_current.unit
+    camera.gain = gain * camera.gain.unit
 
     expected = np.sqrt(dark_current * aperture_area * exposure)
 
@@ -106,14 +110,9 @@ def test_calc_read_noise_only(gain, aperture_area):
     expected = np.sqrt(aperture_area * read_noise**2)
 
     # Create camera instance
-    camera = Camera(
-        data_unit=u.adu,
-        gain=gain * u.electron / u.adu,
-        read_noise=read_noise * u.electron,
-        dark_current=0 * u.electron / u.second,
-        pixel_scale=1 * u.arcsec / u.pixel,
-        max_data_value=40000 * u.adu,
-    )
+    camera = ZERO_CAMERA.copy()
+    camera.read_noise = read_noise * camera.read_noise.unit
+    camera.gain = gain * camera.gain.unit
 
     np.testing.assert_allclose(
         calculate_noise(camera, aperture_area=aperture_area), expected
@@ -128,14 +127,8 @@ def test_calc_sky_only(gain, aperture_area):
     expected = np.sqrt(gain * aperture_area * sky)
 
     # Create camera instance
-    camera = Camera(
-        data_unit=u.adu,
-        gain=gain * u.electron / u.adu,
-        read_noise=0 * u.electron,
-        dark_current=0 * u.electron / u.second,
-        pixel_scale=1 * u.arcsec / u.pixel,
-        max_data_value=40000 * u.adu,
-    )
+    camera = ZERO_CAMERA.copy()
+    camera.gain = gain * camera.gain.unit
 
     np.testing.assert_allclose(
         calculate_noise(camera, aperture_area=aperture_area, sky_per_pix=sky), expected
@@ -153,14 +146,8 @@ def test_annulus_area_term():
     expected = np.sqrt(gain * aperture_area * (1 + aperture_area / annulus_area) * sky)
 
     # Create camera instance
-    camera = Camera(
-        data_unit=u.adu,
-        gain=gain * u.electron / u.adu,
-        read_noise=0 * u.electron,
-        dark_current=0 * u.electron / u.second,
-        pixel_scale=1 * u.arcsec / u.pixel,
-        max_data_value=40000 * u.adu,
-    )
+    camera = ZERO_CAMERA.copy()
+    camera.gain = gain * camera.gain.unit
 
     np.testing.assert_allclose(
         calculate_noise(
@@ -189,14 +176,10 @@ def test_calc_noise_messy_case(digit, expected):
     read_noise = 12
 
     # Create camera instance
-    camera = Camera(
-        data_unit=u.adu,
-        gain=gain * u.electron / u.adu,
-        read_noise=read_noise * u.electron,
-        dark_current=dark_current * u.electron / u.second,
-        pixel_scale=1 * u.arcsec / u.pixel,
-        max_data_value=40000 * u.adu,
-    )
+    camera = ZERO_CAMERA.copy()
+    camera.gain = gain * camera.gain.unit
+    camera.dark_current = dark_current * camera.dark_current.unit
+    camera.read_noise = read_noise * camera.read_noise.unit
 
     np.testing.assert_allclose(
         calculate_noise(

stellarphot/settings/models.py

@@ -29,6 +29,10 @@ class Camera(BaseModel):
         The gain of the camera in units such the product of `gain`
         times the image data has units equal to that of the `read_noise`.
 
+    name : str
+        The name of the camera; can be anything that helps the user identify
+        the camera.
+
     read_noise : `astropy.units.Quantity`
         The read noise of the camera with units.
 
@@ -53,6 +57,10 @@ class Camera(BaseModel):
         The gain of the camera in units such the product of `gain`
         times the image data has units equal to that of the `read_noise`.
 
+    name : str
+        The name of the camera; can be anything that helps the user identify
+        the camera.
+
     read_noise : `astropy.units.Quantity`
         The read noise of the camera with units.
 
@@ -78,6 +86,7 @@ class Camera(BaseModel):
     >>> from stellarphot.settings import Camera
     >>> camera = Camera(data_unit="adu",
     ...                 gain=1.0 * u.electron / u.adu,
+    ...                 name="test camera",
     ...                 read_noise=1.0 * u.electron,
     ...                 dark_current=0.01 * u.electron / u.second,
     ...                 pixel_scale=0.563 * u.arcsec / u.pixel,
@@ -86,6 +95,8 @@ class Camera(BaseModel):
     Unit("adu")
     >>> camera.gain
     <Quantity 1. electron / adu>
+    >>> camera.name
+    'test camera'
     >>> camera.read_noise
     <Quantity 1. electron>
     >>> camera.dark_current
@@ -103,6 +114,7 @@ class Camera(BaseModel):
         description="unit should be consistent with data and read noise",
         examples=["1.0 electron / adu"],
     )
+    name: str
     read_noise: QuantityType = Field(
         description="unit should be consistent with dark current",
         examples=["10.0 electron"],