Merge pull request #138 from sami2py/default_drifts

Default drifts

CHANGELOG.md

@@ -3,6 +3,7 @@ All notable changes to this project will be documented in this file.
 This project adheres to [Semantic Versioning](http://semver.org/).
 
 ## [next version] - 2021-04-05
+- Added default drift fourier coefficient array accessable from run model
 - Using minimum test version of numpy in accordance with NEP 29
 - Removed the sami2py-1.00.namelist and version.txt files from run_name
 - Bug Fix

sami2py/_core.py

@@ -49,7 +49,7 @@ def run_model(tag='model_run', lat=0, lon=0, alt=300, year=2018, day=1,
               no_scale=1, o2_scale=1, he_scale=1, n2_scale=1, n_scale=1,
               Tinf_scale=1, Tn_scale=1., euv_scale=1,
               wind_scale=1, hwm_model=14,
-              fejer=True, ExB_drifts=np.zeros((10, 2)), ve01=0., exb_scale=1,
+              fejer=True, ExB_drifts=None, ve01=0., exb_scale=1,
               alt_crit=150., cqe=7.e-14,
               clean=False, test=False, fmtout=True, outn=False):
     """Runs SAMI2 and archives the data in path
@@ -188,12 +188,16 @@ def run_model(tag='model_run', lat=0, lon=0, alt=300, year=2018, day=1,
         A True value will use the Fejer-Scherliess model of ExB drifts
         A False value will use a user-specified Fourier series for ExB drifts
         (default = True)
-    ExB_drifts : (10x2 ndarray of floats)
+    ExB_drifts : (10x2 ndarray of floats, string, or NoneType)
         Matrix of Fourier series coefficients dependent on solar local time
         (SLT) in hours where
-        ExB_total = ExB_drifts[i,0]*cos((i+1)*pi*SLT/12)
-                  + ExB_drifts[i,1]*sin((i+1)*pi*SLT/12)
-        (default = np.zeros((10,2)))
+        ExB_total = ExB_drifts[i,0] * cos((i + 1) * pi * SLT / 12)
+                  + ExB_drifts[i,1] * sin((i + 1) * pi * SLT / 12)
+        Alternatively, None will produce 24 lt hrs of 0 m/s drifts everywhere.
+        Using the string 'default' will produce a cosine wave with a
+        maximum magnitude of 30 m/s at local noon and a minimum of -30 m/s
+        at midnight.
+        (default = None)
     ve01 : (float)
         Constant offset for Fourier ExB drifts (m/s)
         (default=0)
@@ -282,8 +286,19 @@ def _generate_drift_info(fejer, ExB_drifts=None):
     """
     drift_info = _generate_fortran_bool(fejer)
     if not fejer:
-        if ExB_drifts.shape != (10, 2):
-            raise Exception('Invalid ExB drift shape!  Must be 10x2 ndarray.')
+        if ExB_drifts is None:
+            ExB_drifts = np.zeros((10, 2))
+
+        if isinstance(ExB_drifts, str) and ExB_drifts == 'default':
+            ExB_drifts = np.zeros((10, 2))
+            ExB_drifts[0, 0] = -30
+
+        if isinstance(ExB_drifts, np.ndarray) and ExB_drifts.shape != (10, 2):
+            raise ValueError('Invalid ExB drift shape!  Must be 10x2 ndarray.')
+
+        if isinstance(ExB_drifts, str) and ExB_drifts != 'default':
+            raise ValueError('Unrecognized drift name')
+
         np.savetxt('exb.inp', ExB_drifts)
     return drift_info
 

sami2py/tests/test_core.py

@@ -149,3 +149,31 @@ def teardown(self):
         if os.path.exists(self.model_path):
             shutil.rmtree(self.model_path)
         del self.format, self.ref_file, self.model_path, self.filelist
+
+
+class TestDriftGeneration():
+    """Testing of the _core function _generate_drift_info"""
+
+    def setup(self):
+        f = open('exb.inp', 'w')
+        f.close()
+
+    def teardown(self):
+        os.remove('exb.inp')
+
+    def test_none_drifts(self):
+        empty_drift = np.zeros((10, 2))
+        sami2py._core._generate_drift_info(False, None)
+        drifts = np.loadtxt('exb.inp')
+        assert np.array_equal(drifts, empty_drift)
+
+    def test_default_drifts(self):
+        default = np.zeros((10, 2))
+        default[0, 0] = -30
+        sami2py._core._generate_drift_info(False, 'default')
+        drifts = np.loadtxt('exb.inp')
+        assert np.array_equal(drifts, default)
+
+    def test_bad_string(self):
+        with pytest.raises(Exception):
+            sami2py._core._generate_drift_info(False, 'really_cool_drifts_probably')