add image cadence output parameter, improve self test coverage and ro…

…bustness

dascutils/io.py

@@ -24,6 +24,7 @@ def load(flist:Union[Path,list], azfn:Path=None, elfn:Path=None, treq:list=None,
     reads FITS images and spatial az/el calibration for allsky camera
     Bdecl is in degrees, from IGRF model
     """
+    forig = flist
     warnings.filterwarnings('ignore', category=VerifyWarning)
 
     if isinstance(flist,(str,Path)):
@@ -90,6 +91,9 @@ def load(flist:Union[Path,list], azfn:Path=None, elfn:Path=None, treq:list=None,
         if len(flist)==0:
             raise FileNotFoundError(f'no files found with wavelength(s) {wavelenreq}')
 #%% iterate over image files
+    if len(flist)==0:
+        raise FileNotFoundError(f'no DASC FITS files found in {forig}')
+
     if verbose:
         print('Number of files',len(flist),'with wavelengths',np.unique(wavelen))
 
@@ -137,17 +141,25 @@ def load(flist:Union[Path,list], azfn:Path=None, elfn:Path=None, treq:list=None,
     if wavelen is None:
         data = xarray.Dataset({'unknown': (('time','y','x'), img)},
                                coords={'time':time})
+        if data.time.size > 1: # more than 1 image
+            data.attrs['cadence'] = time[1]-time[0]  # NOTE: assumes uniform kinetic rate
     else:
         data = None
+        cadence = {}
         for w in np.unique(wavelen):
             d = xarray.Dataset({w:(('time','y','x'),img[wavelen==w,...])},
                                coords={'time':time[wavelen==w]})
+            if d.time.size > 1: # more than 1 image
+                cadence[w] = d.time[1] - d.time[0]  # NOTE: assumes uniform kinetic rate
+            else:
+                cadence[w] = None
+
             if data is None:
                 data = d
             else:
                 data = xarray.merge((data,d), join='outer')
 
-
+        data.attrs['cadence'] = cadence
 
     if lla is not None:
         data.attrs['lat']=lla['lat']

tests/test_all.py

@@ -3,6 +3,7 @@
 import numpy as np
 import xarray
 import tempfile
+import pytest
 from datetime import datetime
 from numpy.testing import assert_allclose
 #
@@ -11,11 +12,9 @@
 
 R = Path(__file__).parent
 
-fn = R/'PKR_DASC_0428_20151007_082305.930.FITS'
 azfn = R.parent/'cal/PKR_DASC_20110112_AZ_10deg.fits'
 elfn = R.parent/'cal/PKR_DASC_20110112_EL_10deg.fits'
 
-assert fn.is_file(),f'could not find test data file {fn}'
 assert azfn.is_file(),f'could not find azimuth cal file {azfn}'
 assert elfn.is_file(),f'could not find elevation cal file {azfn}'
 
@@ -26,37 +25,50 @@ def test_timestamp():
     assert_allclose(du.totimestamp(['2012-01-03T08:32:02Z','2012-01-03T08:32:12Z']),
                                    (1325579522.0, 1325579532.0))
 
-def test_lost():
+def test_basic_load():
+# %% expected fail
+    with pytest.raises(FileNotFoundError) as e:
+        with tempfile.TemporaryDirectory() as d:
+            data = dio.load(d)
 # %% most basic
-    data = dio.load(fn)
-    assert data[428].shape == (1,512,512)
-    assert 'az' not in data.data_vars
-# %% a little more complex
-    data = dio.load(fn,azfn,elfn)
+    data = dio.load(R)
     assert isinstance(data, xarray.Dataset)
-    assert 428 in data.data_vars
-    assert data[428].shape == (1,512,512)
 
+    d428 = data[428].dropna(dim='time')
+    assert d428.shape == (1,512,512)
+
+    d558 = data[558].dropna(dim='time')
+    assert d558.shape == (2,512,512)
+
+    d630 = data[630].dropna(dim='time')
+    assert d630.shape == (1,512,512)
+
+    assert 'az' not in data.data_vars
     assert data.lat == 65.126
     assert data.lon == -147.479
-    assert data.time.values == datetime(2015, 10, 7, 8, 23, 5, 930000)
+
+    assert d630.time.values == np.datetime64('2015-10-07T08:23:59.586000')
+    assert data.cadence[558].values == np.timedelta64(12500,'ms')
+
+def test_full_load():
 # %% single time request
-    data = dio.load(fn,azfn,elfn,'2012-01-03T08:32:02')
-    assert data[428].shape == (1,512,512)
+    data = dio.load(R, azfn,elfn,'2012-01-03T08:32:02')
+    assert data[558].shape == (1,512,512)
     assert data.az.shape == (512,512)
     assert data.el.shape == (512,512)
-# %% multi-time request
-    data = dio.load(fn,azfn,elfn,('2012-01-03T08:32:02','2016-01-04'))
-    assert data[428].shape == (1,512,512)
+    assert data.time.item() == datetime(2015, 10, 7, 8, 23, 51, 743000)
+# %% multi-time request and wavelength
+    data = dio.load(R, azfn,elfn,('2012-01-03T08:32:02','2016-01-04'),558)
+    assert data[558].shape == (2,512,512)
 # %% wavelength request
-    data = dio.load(fn,azfn,elfn,None,428)
+    data = dio.load(R, azfn,elfn,None,428)
     assert data[428].shape == (1,512,512)
 
 
-def atest_download():
-    with tempfile.TemporaryDirectory() as d:
-        du.download(('2015-10-07T08:23:04','2015-10-07T08:23:06'),
-                    'ftp://optics.gi.alaska.edu', 'PKR', d)
+def test_download():
+
+    du.download(('2015-10-07T08:23:54','2015-10-07T08:23:56'),
+                'ftp://optics.gi.alaska.edu', 'PKR', R)