added a quick test for calculate_area_fraction

flint/validation.py

@@ -514,12 +514,13 @@ def calculate_area_correction_per_flux(
 
     # Filter out the data
     rms_data = fits.getdata(rms_image_path)
-    rms_data = rms_data[np.isfinite(rms_data)]
+    rms_data = rms_data[np.isfinite(rms_data)].flatten()
 
     # Calculate the cumulative distribution and normalise it to 0..1
-    rms_hist, rms_bins = np.histogram(rms_data.flatten(), bins=500)
+    rms_hist, rms_bins = np.histogram(rms_data, bins=500)
     rms_cdf = np.cumsum(rms_hist)
     rms_cdf = rms_cdf / rms_cdf[-1]
+    assert np.isclose(rms_cdf[-1], 1), "Normalisation of the RMS CDF failed"
 
     # Calculate the bin centers of the histogram / CDF
     rms_bin_centre = 0.5 * (rms_bins[1:] + rms_bins[:-1])

tests/test_validation.py

@@ -7,7 +7,12 @@
 import pkg_resources
 import pytest
 
-from flint.validation import RMSImageInfo, get_parser, get_rms_image_info
+from flint.validation import (
+    RMSImageInfo,
+    get_parser,
+    get_rms_image_info,
+    calculate_area_correction_per_flux,
+)
 
 
 def test_get_parser():
@@ -25,6 +30,22 @@ def rms_path(tmpdir):
     return rms_path
 
 
+def test_calculate_area_correction(rms_path):
+    """This is not an entirely robust check as the rms image is only
+    10 x 15 pixels. More testing for errors in the calling."""
+
+    flux_bin_centres = np.arange(0.00004, 0.01, 0.0001)
+
+    area_frac = calculate_area_correction_per_flux(
+        rms_image_path=rms_path, flux_bin_centre=flux_bin_centres, sigma=3
+    )
+
+    test = np.ones(100)
+    test[:5] = 0.0
+
+    assert np.allclose(test, area_frac)
+
+
 def test_rms_image_info(rms_path):
     rms_info = get_rms_image_info(rms_path=rms_path)