pvlib · mikofski · Sep 5, 2020 · Aug 27, 2020 · Aug 27, 2020 · Aug 27, 2020
diff --git a/ci/requirements-py35-min.yml b/ci/requirements-py35-min.yml
@@ -15,5 +15,6 @@ dependencies:
     - pip:
         - numpy==1.12.0
         - pandas==0.22.0
+        - scipy==1.2.0
         - pytest-rerunfailures # conda version is >3.6
         - pytest-remotedata # conda package is 0.3.0, needs > 0.3.1
diff --git a/docs/sphinx/source/whatsnew/v0.8.0.rst b/docs/sphinx/source/whatsnew/v0.8.0.rst
@@ -144,6 +144,8 @@ Documentation
 Requirements
 ~~~~~~~~~~~~
 * Minimum pandas version increased to v0.22.0, released Dec 31, 2017. (:pull:`1003`)
+* Scipy >= v1.2.0, released Dec 17, 2018, is now a required dependency
+  rather an optional dependency. (:issue:`972`, :pull:`1035`)
 
 Contributors
 ~~~~~~~~~~~~

diff --git a/pvlib/scaling.py b/pvlib/scaling.py
@@ -6,6 +6,9 @@
 import numpy as np
 import pandas as pd
 
+import scipy.optimize
+from scipy.spatial.distance import pdist
+
 
 def wvm(clearsky_index, positions, cloud_speed, dt=None):
     """
@@ -59,12 +62,6 @@ def wvm(clearsky_index, positions, cloud_speed, dt=None):
 
     # Added by Joe Ranalli (@jranalli), Penn State Hazleton, 2019
 
-    try:
-        import scipy.optimize
-        from scipy.spatial.distance import pdist
-    except ImportError:
-        raise ImportError("The WVM function requires scipy.")
-
     pos = np.array(positions)
     dist = pdist(pos, 'euclidean')
     wavelet, tmscales = _compute_wavelet(clearsky_index, dt)

diff --git a/pvlib/singlediode.py b/pvlib/singlediode.py
@@ -7,23 +7,11 @@
 import numpy as np
 from pvlib.tools import _golden_sect_DataFrame
 
-# Try to import brentq from scipy to use when s
8000
pecified in bishop88_i_from_v,
-# bishop88_v_from_i, and bishop88_mpp methods below. If not imported, raises
-# ImportError when 'brentq' method is specified for those methods.
-try:
-    from scipy.optimize import brentq
-except ImportError:
-    def brentq(*a, **kw):
-        raise ImportError(
-            "brentq couldn't be imported. Is SciPy installed?")
-
-# FIXME: change this to newton when scipy-1.2 is released
-try:
-    from scipy.optimize import _array_newton
-except ImportError:
-    from pvlib.tools import _array_newton
-# rename newton and set keyword arguments
-newton = partial(_array_newton, tol=1e-6, maxiter=100, fprime2=None)
+from scipy.optimize import brentq, newton
+from scipy.special import lambertw
+
+# set keyword arguments for all uses of newton in this module
+newton = partial(newton, tol=1e-6, maxiter=100, fprime2=None)
 
 # intrinsic voltage per cell junction for a:Si, CdTe, Mertens et al.
 VOLTAGE_BUILTIN = 0.9  # [V]
@@ -510,11 +498,6 @@ def _prepare_newton_inputs(i_or_v_tup, args, v0):
 
 def _lambertw_v_from_i(resistance_shunt, resistance_series, nNsVth, current,
                        saturation_current, photocurrent):
-    try:
-        from scipy.special import lambertw
-    except ImportError:
-        raise ImportError('This function requires scipy')
-
     # Record if inputs were all scalar
     output_is_scalar = all(map(np.isscalar,
                                [resistance_shunt, resistance_series, nNsVth,
@@ -592,11 +575,6 @@ def _lambertw_v_from_i(resistance_shunt, resistance_series, nNsVth, current,
 
 def _lambertw_i_from_v(resistance_shunt, resistance_series, nNsVth, voltage,
                        saturation_current, photocurrent):
-    try:
-        from scipy.special import lambertw
-    except ImportError:
-        raise ImportError('This function requires scipy')
-    
     # Record if inputs were all scalar
     output_is_scalar = all(map(np.isscalar,
                                [resistance_shunt, resistance_series, nNsVth,

diff --git a/pvlib/soiling.py b/pvlib/soiling.py
@@ -6,6 +6,8 @@
 import datetime
 import numpy as np
 import pandas as pd
+from scipy.special import erf
+
 from pvlib.tools import cosd
 
 
@@ -62,11 +64,6 @@ def hsu(rainfall, cleaning_threshold, tilt, pm2_5, pm10,
        Change. J. Seinfeld and S. Pandis. Wiley and Sons 2001.
 
     """
-    try:
-        from scipy.special import erf
-    except ImportError:
-        raise ImportError("The pvlib.soiling.hsu function requires scipy.")
-
     # never use mutable input arguments
     if depo_veloc is None:
         depo_veloc = {'2_5': 0.0009, '10': 0.004}

diff --git a/pvlib/solarposition.py b/pvlib/solarposition.py
@@ -20,6 +20,7 @@
 
 import numpy as np
 import pandas as pd
+import scipy.optimize as so
 import warnings
 
 from pvlib import atmosphere
@@ -911,12 +912,6 @@ def calc_time(lower_bound, upper_bound, latitude, longitude, attribute, value,
         If the given attribute is not an attribute of a
         PyEphem.Sun object.
     """
-
-    try:
-        import scipy.optimize as so
-    except ImportError:
-        raise ImportError('The calc_time function requires scipy')
-
     obs, sun = _ephem_setup(latitude, longitude, altitude,
                             pressure, temperature, horizon)
 

diff --git a/pvlib/tests/conftest.py b/pvlib/tests/conftest.py
@@ -2,7 +2,6 @@
 import platform
 import warnings
 
-import numpy as np
 import pandas as pd
 from pkg_resources import parse_version
 import pytest
@@ -81,14 +80,6 @@ def assert_frame_equal(left, right, **kwargs):
 skip_windows = pytest.mark.skipif(platform_is_windows,
                                   reason='does not run on windows')
 
-try:
-    import scipy
-    has_scipy = True
-except ImportError:
-    has_scipy = False
-
-requires_scipy = pytest.mark.skipif(not has_scipy, reason='requires scipy')
-
 
 try:
     import statsmodels  # noqa: F401
@@ -118,14 +109,6 @@ def assert_frame_equal(left, right, **kwargs):
 requires_ephem = pytest.mark.skipif(not has_ephem, reason='requires ephem')
 
 
-def numpy_1_10():
-    return parse_version(np.__version__) >= parse_version('1.10.0')
-
-
-needs_numpy_1_10 = pytest.mark.skipif(
-    not numpy_1_10(), reason='requires numpy 1.10 or greater')
-
-
 def has_spa_c():
     try:
         from pvlib.spa_c_files.spa_py import spa_calc

diff --git a/pvlib/tests/ivtools/test_sde.py b/pvlib/tests/ivtools/test_sde.py
@@ -2,15 +2,13 @@
 import pytest
 from pvlib import pvsystem
 from pvlib.ivtools import sde
-from pvlib.tests.conftest import requires_scipy
 
 
 @pytest.fixture
 def get_test_iv_params():
     return {'IL': 8.0, 'I0': 5e-10, 'Rs': 0.2, 'Rsh': 1000, 'nNsVth': 1.61864}
 
 
-@requires_scipy
 def test_fit_sandia_simple(get_test_iv_params, get_bad_iv_curves):
     test_params = get_test_iv_params
     testcurve = pvsystem.singlediode(photocurrent=test_params['IL'],
@@ -41,7 +39,6 @@ def test_fit_sandia_simple(get_test_iv_params, get_bad_iv_curves):
     assert np.allclose(result, expected, rtol=5e-5)
 
 
-@requires_scipy
 def test_fit_sandia_simple_bad_iv(get_bad_iv_curves):
     # bad IV curves for coverage of if/then in sde._sandia_simple_params
     v1, i1, v2, i2 = get_bad_iv_curves

diff --git a/pvlib/tests/ivtools/test_sdm.py b/pvlib/tests/ivtools/test_sdm.py
@@ -6,8 +6,7 @@
 from pvlib.ivtools import sdm
 from pvlib import pvsystem
 
-from pvlib.tests.conftest import requires_scipy, requires_pysam
-from pvlib.tests.conftest import requires_statsmodels
+from pvlib.tests.conftest import requires_pysam, requires_statsmodels
 
 from conftest import DATA_DIR
 
@@ -61,7 +60,6 @@ def test_fit_cec_sam_estimation_failure(cec_params_cansol_cs5p_220p):
                         gamma_pmp=0.0055, cells_in_series=1, temp_ref=25)
 
 
-@requires_scipy
 def test_fit_desoto():
     result, _ = sdm.fit_desoto(v_mp=31.0, i_mp=8.71, v_oc=38.3, i_sc=9.43,
                                alpha_sc=0.005658, beta_voc=-0.13788,
@@ -80,7 +78,6 @@ def test_fit_desoto():
                        rtol=1e-4)
 
 
-@requires_scipy
 def test_fit_desoto_failure():
     with pytest.raises(RuntimeError) as exc:
         sdm.fit_desoto(v_mp=31.0, i_mp=8.71, v_oc=38.3, i_sc=9.43,
@@ -89,7 +86,6 @@ def test_fit_desoto_failure():
     assert ('Parameter estimation failed') in str(exc.value)
 
 
-@requires_scipy
 @requires_statsmodels
 def test_fit_desoto_sandia(cec_params_cansol_cs5p_220p):
     # this test computes a set of IV curves for the input fixture, fits
@@ -224,7 +220,6 @@ def _read_pvsyst_expected(datafile):
     return pvsyst_specs, pvsyst
 
 
-@requires_scipy
 @requires_statsmodels
 def test_fit_pvsyst_sandia(npts=3000):
 
@@ -295,7 +290,6 @@ def test_fit_pvsyst_sandia(npts=3000):
         equal_nan=True, rtol=0.63)
 
 
-@requires_scipy
 @pytest.mark.parametrize('vmp, imp, iph, io, rs, rsh, nnsvth, expected', [
     (2., 2., 2., 2., 2., 2., 2., np.nan),
     (2., 2., 0., 2., 2., 2., 2., np.nan),
@@ -309,14 +303,12 @@ def test__update_rsh_fixed_pt_nans(vmp, imp, iph, io, rs, rsh, nnsvth,
     assert np.all(np.isnan(outrsh))
 
 
-@requires_scipy
 def test__update_rsh_fixed_pt_vmp0():
     outrsh = sdm._update_rsh_fixed_pt(vmp=0., imp=2., iph=2., io=2., rs=2.,
                                       rsh=2., nnsvth=2.)
     np.testing.assert_allclose(outrsh, np.array([502.]), atol=.0001)
 
 
-@requires_scipy
 def test__update_rsh_fixed_pt_vector():
     outrsh = sdm._update_rsh_fixed_pt(rsh=np.array([-1., 3, .5, 2.]),
                                       rs=np.array([1., -.5, 2., 2.]),
@@ -329,7 +321,6 @@ def test__update_rsh_fixed_pt_vector():
     np.testing.assert_allclose(outrsh[3], np.array([502.]), atol=.0001)
 
 
-@requires_scipy
 @pytest.mark.parametrize('voc, iph, io, rs, rsh, nnsvth, expected', [
     (2., 2., 2., 2., 2., 2., 0.5911),
     (2., 2., 2., 0., 2., 2., 0.5911),
@@ -341,7 +332,6 @@ def test__update_io(voc, iph, io, rs, rsh, nnsvth, expected):
     np.testing.assert_allclose(outio, expected, atol=.0001)
 
 
-@requires_scipy
 @pytest.mark.parametrize('voc, iph, io, rs, rsh, nnsvth', [
     (2., 2., 2., 2., 2., 0.),
     (-1., -1., -1., -1., -1., -1.)])
@@ -350,7 +340,6 @@ def test__update_io_nan(voc, iph, io, rs, rsh, nnsvth):
     assert np.isnan(outio)
 
 
-@requires_scipy
 @pytest.mark.parametrize('vmp, imp, iph, io, rs, rsh, nnsvth, expected', [
     (2., 2., 2., 2., 2., 2., 2., (1.8726, 2.)),
     (2., 0., 2., 2., 2., 2., 2., (1.8726, 3.4537)),
@@ -362,7 +351,6 @@ def test__calc_theta_phi_exact(vmp, imp, iph, io, rs, rsh, nnsvth, expected):
     np.testing.assert_allclose(phi, expected[1], atol=.0001)
 
 
-@requires_scipy
 @pytest.mark.parametrize('vmp, imp, iph, io, rs, rsh, nnsvth', [
     (2., 2., 2., 0., 2., 2., 2.),
     (2., 2., 2., 2., 2., 2., 0.),
@@ -373,15 +361,13 @@ def test__calc_theta_phi_exact_both_nan(vmp, imp, iph, io, rs, rsh, nnsvth):
     assert np.isnan(phi)
 
 
-@requires_scipy
 def test__calc_theta_phi_exact_one_nan():
     theta, phi = sdm._calc_theta_phi_exact(imp=2., iph=2., vmp=2., io=2.,
                                            nnsvth=2., rs=0., rsh=2.)
     assert np.isnan(theta)
     np.testing.assert_allclose(phi, 2., atol=.0001)
 
 
-@requires_scipy
 def test__calc_theta_phi_exact_vector():
     theta, phi = sdm._calc_theta_phi_exact(imp=np.array([1., -1.]),
                                            iph=np.array([-1., 1.]),

diff --git a/pvlib/tests/test_clearsky.py b/pvlib/tests/test_clearsky.py
@@ -15,7 +15,7 @@
 from pvlib import atmosphere
 from pvlib import irradiance
 
-from conftest import requires_scipy, requires_tables, DATA_DIR
+from conftest import requires_tables, DATA_DIR
 
 
 def test_ineichen_series():
@@ -546,7 +546,6 @@ def detect_clearsky_data():
     return expected, cs
 
 
-@requires_scipy
 def test_detect_clearsky(detect_clearsky_data):
     expected, cs = detect_clearsky_data
     clear_samples = clearsky.detect_clearsky(
@@ -555,7 +554,6 @@ def test_detect_clearsky(detect_clearsky_data):
                         check_dtype=False, check_names=False)
 
 
-@requires_scipy
 def test_detect_clearsky_components(detect_clearsky_data):
     expected, cs = detect_clearsky_data
     clear_samples, components, alpha = clearsky.detect_clearsky(
@@ -566,7 +564,6 @@ def test_detect_clearsky_components(detect_clearsky_data):
     assert np.allclose(alpha, 0.9633903181941296)
 
 
-@requires_scipy
 def test_detect_clearsky_iterations(detect_clearsky_data):
     expected, cs = detect_clearsky_data
     alpha = 1.0448
@@ -581,7 +578,6 @@ def test_detect_clearsky_iterations(detect_clearsky_data):
                         check_dtype=False, check_names=False)
 
 
-@requires_scipy
 def test_detect_clearsky_kwargs(detect_clearsky_data):
     expected, cs = detect_clearsky_data
     clear_samples = clearsky.detect_clearsky(
@@ -591,7 +587,6 @@ def test_detect_clearsky_kwargs(detect_clearsky_data):
     assert clear_samples.all()
 
 
-@requires_scipy
 def test_detect_clearsky_window(detect_clearsky_data):
     expected, cs = detect_clearsky_data
     clear_samples = clearsky.detect_clearsky(
@@ -602,7 +597,6 @@ def test_detect_clearsky_window(detect_clearsky_data):
                         check_dtype=False, check_names=False)
 
 
-@requires_scipy
 def test_detect_clearsky_arrays(detect_clearsky_data):
     expected, cs = detect_clearsky_data
     clear_samples = clearsky.detect_clearsky(
@@ -611,7 +605,6 @@ def test_detect_clearsky_arrays(detect_clearsky_data):
     assert (clear_samples == expected['Clear or not'].values).all()
 
 
-@requires_scipy
 def test_detect_clearsky_irregular_times(detect_clearsky_data):
     expected, cs = detect_clearsky_data
     times = cs.index.values.copy()