Merge pull request #1 from snowman2/return_back_azimuth

REF: Use cython for reverse_azimuth

pyproj/_geod.pyx

@@ -5,6 +5,7 @@ from libc.math cimport ceil, isnan, round
 
 from pyproj._compat cimport cstrencode, empty_array
 
+import math
 from collections import namedtuple
 
 from pyproj.enums import GeodIntermediateFlag
@@ -65,6 +66,24 @@ cdef int GEOD_INTER_FLAG_AZIS_DISCARD = GeodIntermediateFlag.AZIS_DISCARD
 cdef int GEOD_INTER_FLAG_AZIS_KEEP = GeodIntermediateFlag.AZIS_KEEP
 
 
+cdef double _reverse_azimuth(double azi, double factor) nogil:
+    if azi > 0:
+        azi = azi - factor
+    else:
+        azi = azi + factor
+    return azi
+
+def reverse_azimuth(object azi, bint radians=False):
+    cdef PyBuffWriteManager azibuff = PyBuffWriteManager(azi)
+    cdef Py_ssize_t iii
+    cdef double factor = 180
+    if radians:
+        factor = math.pi
+    with nogil:
+        for iii in range(azibuff.len):
+            azibuff.data[iii] = _reverse_azimuth(azibuff.data[iii], factor=factor)
+
+
 cdef class Geod:
     def __init__(self, double a, double f, bint sphere, double b, double es):
         geod_init(&self._geod_geodesic, <double> a, <double> f)
@@ -137,10 +156,7 @@ cdef class Geod:
                 # forward azimuth needs to be flipped 180 degrees
                 # to match the (back azimuth) output of PROJ geod utilities.
                 if return_back_azimuth:
-                    if pazi2 > 0:
-                        pazi2 = pazi2 - 180.
-                    else:
-                        pazi2 = pazi2 + 180.
+                    pazi2 = _reverse_azimuth(pazi2, factor=180)
                 if not radians:
                     lonbuff.data[iii] = plon2
                     latbuff.data[iii] = plat2
@@ -201,10 +217,7 @@ cdef class Geod:
                 # forward azimuth needs to be flipped 180 degrees
                 # to match the (back azimuth) output of PROJ geod utilities.
                 if return_back_azimuth:
-                    if pazi2 > 0:
-                        pazi2 = pazi2 - 180.
-                    else:
-                        pazi2 = pazi2 + 180.
+                    pazi2 = _reverse_azimuth(pazi2, factor=180)
                 if radians:
                     lon1buff.data[iii] = _DG2RAD * pazi1
                     lat1buff.data[iii] = _DG2RAD * pazi2
@@ -327,10 +340,7 @@ cdef class Geod:
                     # forward azimuth needs to be flipped 180 degrees
                     # to match the (back azimuth) output of PROJ geod utilities.
                     if return_back_azimuth:
-                        if pazi2 > 0:
-                            pazi2 = pazi2 - 180.
-                        else:
-                            pazi2 = pazi2 + 180.
+                        pazi2 =_reverse_azimuth(pazi2, factor=180)
                     azis_buff.data[iii] = pazi2
 
         return GeodIntermediateReturn(

pyproj/geod.py

@@ -23,6 +23,7 @@
 
 from pyproj._geod import Geod as _Geod
 from pyproj._geod import GeodIntermediateReturn, geodesic_version_str
+from pyproj._geod import reverse_azimuth as _reverse_azimuth
 from pyproj.enums import GeodIntermediateFlag
 from pyproj.exceptions import GeodError
 from pyproj.list import get_ellps_map
@@ -1117,47 +1118,38 @@ def __eq__(self, other: Any) -> bool:
         return self.__repr__() == other.__repr__()
 
 
-try:
-    import numpy as np  # type: ignore  # pylint: disable=import-outside-toplevel
-
-    def reverse_azimuth(azi: Any, radians: bool = False) -> Any:
-        """
-        Reverses the given azimuth (forward <-> backwards)
-
-        Parameters
-        ----------
-        azi: float or array, :class:`numpy.ndarray`
-            azimuth
-        radians: bool, default=False
-            If True, the input data is assumed to be in radians.
-            Otherwise, the data is assumed to be in degrees.
+def reverse_azimuth(azi: Any, radians: bool = False) -> Any:
+    """
+    Reverses the given azimuth (forward <-> backwards)
 
-        Returns
-        -------
-        float or array, :class:`numpy.ndarray`
-            the reversed azimuth (forward <-> backwards)
-        """
-        factor = math.pi if radians else 180.0
-        return azi - np.copysign(factor, azi)
+    .. versionadded:: 3.5.0
 
-except ImportError:
+    Accepted numeric scalar or array:
 
-    def reverse_azimuth(azi: Any, radians: bool = False) -> Any:
-        """
-        Reverses the given azimuth (forward <-> backwards)
+    - :class:`int`
+    - :class:`float`
+    - :class:`numpy.floating`
+    - :class:`numpy.integer`
+    - :class:`list`
+    - :class:`tuple`
+    - :class:`array.array`
+    - :class:`numpy.ndarray`
+    - :class:`xarray.DataArray`
+    - :class:`pandas.Series`
 
-        Parameters
-        ----------
-        azi: float
-            azimuth
-        radians: bool, default=False
-            If True, the input data is assumed to be in radians.
-            Otherwise, the data is assumed to be in degrees.
+    Parameters
+    ----------
+    azi: scalar or array
+        The azimuth.
+    radians: bool, default=False
+        If True, the input data is assumed to be in radians.
+        Otherwise, the data is assumed to be in degrees.
 
-        Returns
-        -------
-        float
-            the reversed azimuth (forward <-> backwards)
-        """
-        factor = math.pi if radians else 180.0
-        return azi - math.copysign(factor, azi)
+    Returns
+    -------
+    scalar or array:
+        The reversed azimuth (forward <-> backwards)
+    """
+    inazi, azi_data_type = _copytobuffer(azi)
+    _reverse_azimuth(inazi, radians=radians)
+    return _convertback(azi_data_type, inazi)