DEP: deprecation warnings for special.lpn and [c]lpmn

Author: jorenham

scipy/special/_basic.py

@@ -21,6 +21,7 @@
 from ._comb import _comb_int
 from ._multiufuncs import (assoc_legendre_p_all,
                            legendre_p_all)
+from scipy._lib.deprecation import _deprecated
 
 
 __all__ = [
@@ -87,6 +88,11 @@
 ]
 
 
+__DEPRECATION_MSG_1_15 = (
+    "`scipy.special.{}` is deprecated as of SciPy 1.15.0 and will be "
+    "removed in SciPy 1.17.0. Please use `scipy.special.{}` instead."
+)
+
 # mapping k to last n such that factorialk(n, k) < np.iinfo(np.int64).max
 _FACTORIALK_LIMITS_64BITS = {1: 20, 2: 33, 3: 44, 4: 54, 5: 65,
                              6: 74, 7: 84, 8: 93, 9: 101}
@@ -1703,6 +1709,7 @@ def mathieu_odd_coef(m, q):
     return fc[:km]
 
 
+@_deprecated(__DEPRECATION_MSG_1_15.format("lpmn", "assoc_legendre_p_all"))
 def lpmn(m, n, z):
     """Sequence of associated Legendre functions of the first kind.
 
@@ -1715,8 +1722,8 @@ def lpmn(m, n, z):
     use clpmn instead.
 
     .. deprecated:: 1.15.0
-        This function is deprecated and will be removed in a future version.
-        Use `scipy.special.assoc_legendre_p_all` instead.
+        This function is deprecated and will be removed in SciPy 1.17.0.
+        Please `scipy.special.assoc_legendre_p_all` instead.
 
     Parameters
     ----------
@@ -1782,6 +1789,7 @@ def lpmn(m, n, z):
     return p, pd
 
 
+@_deprecated(__DEPRECATION_MSG_1_15.format("clpmn", "assoc_legendre_p_all"))
 def clpmn(m, n, z, type=3):
     """Associated Legendre function of the first kind for complex arguments.
 
@@ -1791,8 +1799,8 @@ def clpmn(m, n, z, type=3):
     ``Pmn'(z)`` for all orders from ``0..m`` and degrees from ``0..n``.
 
     .. deprecated:: 1.15.0
-        This function is deprecated and will be removed in a future version.
-        Use `scipy.special.assoc_legendre_p_all` instead.
+        This function is deprecated and will be removed in SciPy 1.17.0.
+        Please use `scipy.special.assoc_legendre_p_all` instead.
 
     Parameters
     ----------
@@ -2033,6 +2041,7 @@ def euler(n):
     return _specfun.eulerb(n1)[:(n+1)]
 
 
+@_deprecated(__DEPRECATION_MSG_1_15.format("lpn", "legendre_p_all"))
 def lpn(n, z):
     """Legendre function of the first kind.
 
@@ -2042,8 +2051,8 @@ def lpn(n, z):
     See also special.legendre for polynomial class.
 
     .. deprecated:: 1.15.0
-        This function is deprecated and will be removed in a future version.
-        Use `scipy.special.legendre_p_all` instead.
+        This function is deprecated and will be removed in SciPy 1.17.0.
+        Please use `scipy.special.legendre_p_all` instead.
 
     References
     ----------
@@ -3464,7 +3473,7 @@ def zeta(x, q=None, out=None):
         ``None``, complex inputs `x` are supported. If `q` is not ``None``,
         then currently only real inputs `x` with ``x >= 1`` are supported,
         even when ``q = 1.0`` (corresponding to the Riemann zeta function).
-        
+
     out : ndarray, optional
         Output array for the computed values.
 
@@ -3530,7 +3539,7 @@ def zeta(x, q=None, out=None):
     else:
         return _ufuncs._zeta(x, q, out)
 
-      
+
 def softplus(x, **kwargs):
     r"""
     Compute the softplus function element-wise.
@@ -3554,7 +3563,7 @@ def softplus(x, **kwargs):
     Examples
     --------
     >>> from scipy import special
-    
+
     >>> special.softplus(0)
     0.6931471805599453
 

scipy/special/tests/test_basic.py

@@ -41,6 +41,7 @@
 from scipy.special import elliprc, elliprd, elliprf, elliprg, elliprj
 from scipy.special import softplus
 from scipy.special import mathieu_odd_coef, mathieu_even_coef, stirling2
+from scipy.special import lpn, lpmn, clpmn
 from scipy._lib._util import np_long, np_ulong
 from scipy._lib._array_api import xp_assert_close, xp_assert_equal, SCIPY_ARRAY_API
 
@@ -4633,3 +4634,17 @@ def test_temme_rel_max_error(self):
             denom = stirling2([n], k_entries, exact=True)
             num = denom - stirling2([n], k_entries, exact=False)
             assert np.max(np.abs(num / denom)) < 2e-5
+
+
+class TestLegendreDeprecation:
+
+    def test_warn_lpn(self):
+        msg = "`scipy.special.lpn` is deprecated..."
+        with pytest.deprecated_call(match=msg):
+            _ = lpn(1, 0)
+
+    @pytest.mark.parametrize("xlpmn", [lpmn, clpmn])
+    def test_warn_xlpmn(self, xlpmn):
+        message = f"`scipy.special.{xlpmn.__name__}` is deprecated..."
+        with pytest.deprecated_call(match=message):
+            _ = xlpmn(1, 1, 0)