Merge pull request #614 from mrava87/fix-chirpradon3d

Bug: fix pyfftw handling in chirpradon3d

pylops/signalprocessing/chirpradon3d.py

@@ -14,8 +14,6 @@
 pyfftw_message = deps.pyfftw_import("the chirpradon3d module")
 
 if pyfftw_message is None:
-    import pyfftw
-
     from ._chirpradon3d import _chirp_radon_3d_fftw
 
 logging.basicConfig(format="%(levelname)s: %(message)s", level=logging.WARNING)
@@ -101,23 +99,23 @@ def __init__(
 
     @reshaped
     def _matvec(self, x: NDArray) -> NDArray:
-        if self.engine == "fftw" and pyfftw is not None:
+        if self.engine == "fftw" and pyfftw_message is None:
             return _chirp_radon_3d_fftw(
                 x, self.dt, self.dy, self.dx, self.pmax, mode="f", **self.kwargs_fftw
             )
         return _chirp_radon_3d(x, self.dt, self.dy, self.dx, self.pmax, mode="f")
 
     @reshaped
     def _rmatvec(self, x: NDArray) -> NDArray:
-        if self.engine == "fftw" and pyfftw is not None:
+        if self.engine == "fftw" and pyfftw_message is None:
             return _chirp_radon_3d_fftw(
                 x, self.dt, self.dy, self.dx, self.pmax, mode="a", **self.kwargs_fftw
             )
         return _chirp_radon_3d(x, self.dt, self.dy, self.dx, self.pmax, mode="a")
 
     def inverse(self, x: NDArray) -> NDArray:
         x = x.reshape(self.dimsd)
-        if self.engine == "fftw" and pyfftw is not None:
+        if self.engine == "fftw" and pyfftw_message is None:
             y = _chirp_radon_3d_fftw(
                 x, self.dt, self.dy, self.dx, self.pmax, mode="i", **self.kwargs_fftw
             )