put back deltaT test

pvlib · kandersolar · Jun 23, 2023 · Jun 12, 2023 · Jun 12, 2023 · Jun 12, 2023
commit c4a1adfe972c2ec7ee442c193217b8c36c60f621
diff --git a/pvlib/tests/test_spa.py b/pvlib/tests/test_spa.py
@@ -76,6 +76,24 @@
 theta0 = 90 - e0
 Gamma = 14.340241
 Phi = 194.340241
+year = 1985
+month = 2
+year_array = np.array([-499, 500, 1000, 1500, 1800, 1860, 1900, 1950,
+                       1970, 1985, 1990, 2000, 2005, 2050, 2150])
+# `month_array` is used with `year_array` in `test_calculate_deltat`.
+# Both arrays need to have the same length for the test, hence the duplicates.
+month_array = np.array([1, 2, 3, 4, 5, 6, 6, 7, 8, 9, 10, 11, 12, 12, 12])
+dt_actual = 54.413442486
+dt_actual_array = np.array([1.7184831e+04, 5.7088051e+03, 1.5730419e+03,
+                            1.9801820e+02, 1.3596506e+01, 7.8316585e+00,
+                            -2.1171894e+00, 2.9289261e+01, 4.0824887e+01,
+                            5.4724581e+01, 5.7426651e+01, 6.4108015e+01,
+                            6.5038015e+01, 9.4952955e+01, 3.3050693e+02])
+mix_year_array = np.full((10), year)
+mix_month_array = np.full((10), month)
+mix_year_actual = np.full((10), dt_actual)
+mix_month_actual = mix_year_actual
+

 class SpaBase:
    """Test functions common to numpy and numba spa"""
@@ -341,6 +359,19 @@ def test_earthsun_distance(self):
        result = self.spa.earthsun_distance(unixtimes, 64.0, 1)
        assert_almost_equal(R, result, 6)

+    def test_calculate_deltat(self):
+        result_mix_year = self.spa.calculate_deltat(mix_year_array, month)
+        assert_almost_equal(mix_year_actual, result_mix_year)
+
+        result_mix_month = self.spa.calculate_deltat(year, mix_month_array)
+        assert_almost_equal(mix_month_actual, result_mix_month)
+
+        result_array = self.spa.calculate_deltat(year_array, month_array)
+        assert_almost_equal(dt_actual_array, result_array, 3)
+
+        result_scalar = self.spa.calculate_deltat(year, month)
+        assert_almost_equal(dt_actual, result_scalar)
+

 class NumpySpaTest(unittest.TestCase, SpaBase):
    """Import spa without compiling to numba then run tests"""