MultiFab: to_numpy/cupy

src/amrex/MultiFab.py

@@ -7,7 +7,7 @@
 """
 
 
-def mf_to_numpy(self, copy=False, order="F"):
+def mf_to_numpy(amr, self, copy=False, order="F"):
     """
     Provide a Numpy view into a MultiFab.
 
@@ -29,13 +29,24 @@ def mf_to_numpy(self, copy=False, order="F"):
 
     Returns
     -------
-    list of np.array
+    list of numpy.array
         A list of numpy n-dimensional arrays, for each local block in the
         MultiFab.
     """
+    mf = self
+    if copy:
+        mf = amr.MultiFab(
+            self.box_array(),
+            self.dm(),
+            self.n_comp(),
+            self.n_grow_vect(),
+            amr.MFInfo().set_arena(amr.The_Pinned_Arena()),
+        )
+        amr.dtoh_memcpy(mf, self)
+
     views = []
-    for mfi in self:
-        views.append(self.array(mfi).to_numpy(copy, order))
+    for mfi in mf:
+        views.append(mf.array(mfi).to_numpy(copy=False, order=order))
 
     return views
 
@@ -80,15 +91,11 @@ def mf_to_cupy(self, copy=False, order="F"):
 
 def register_MultiFab_extension(amr):
     """MultiFab helper methods"""
-    import inspect
-    import sys
-
-    # register member functions for every MultiFab* type
-    for _, MultiFab_type in inspect.getmembers(
-        sys.modules[amr.__name__],
-        lambda member: inspect.isclass(member)
-        and member.__module__ == amr.__name__
-        and member.__name__.startswith("MultiFab"),
-    ):
-        MultiFab_type.to_numpy = mf_to_numpy
-        MultiFab_type.to_cupy = mf_to_cupy
+
+    # register member functions for the MultiFab type
+    amr.MultiFab.to_numpy = lambda self, copy=False, order="F": mf_to_numpy(
+        amr, self, copy, order
+    )
+    amr.MultiFab.to_numpy.__doc__ = mf_to_numpy.__doc__
+
+    amr.MultiFab.to_cupy = mf_to_cupy

src/amrex/space1d/__init__.py

@@ -46,10 +46,12 @@ def Print(*args, **kwargs):
 
 from ..Array4 import register_Array4_extension
 from ..ArrayOfStructs import register_AoS_extension
+from ..MultiFab import register_MultiFab_extension
 from ..PODVector import register_PODVector_extension
 from ..StructOfArrays import register_SoA_extension
 
 register_Array4_extension(amrex_1d_pybind)
+register_MultiFab_extension(amrex_1d_pybind)
 register_PODVector_extension(amrex_1d_pybind)
 register_SoA_extension(amrex_1d_pybind)
 register_AoS_extension(amrex_1d_pybind)

src/amrex/space1d/__init__.pyi

@@ -38,6 +38,7 @@ import os as os
 
 from amrex.Array4 import register_Array4_extension
 from amrex.ArrayOfStructs import register_AoS_extension
+from amrex.MultiFab import register_MultiFab_extension
 from amrex.PODVector import register_PODVector_extension
 from amrex.StructOfArrays import register_SoA_extension
 from amrex.space1d.amrex_1d_pybind import (
@@ -461,6 +462,7 @@ __all__ = [
     "refine",
     "register_AoS_extension",
     "register_Array4_extension",
+    "register_MultiFab_extension",
     "register_PODVector_extension",
     "register_SoA_extension",
     "size",

src/amrex/space1d/amrex_1d_pybind/__init__.pyi

@@ -4043,6 +4043,67 @@ class MultiFab(FabArray_FArrayBox):
         """
         Same as sum with local=false, but for non-cell-centered data, thisskips non-unique points that are owned by multiple boxes.
         """
+    def to_cupy(self, copy=False, order="F"):
+        """
+
+        Provide a Cupy view into a MultiFab.
+
+        Note on the order of indices:
+        By default, this is as in AMReX in Fortran contiguous order, indexing as
+        x,y,z. This has performance implications for use in external libraries such
+        as cupy.
+        The order="C" option will index as z,y,x and perform better with cupy.
+        https://github.com/AMReX-Codes/pyamrex/issues/55#issuecomment-1579610074
+
+        Parameters
+        ----------
+        self : amrex.MultiFab
+            A MultiFab class in pyAMReX
+        copy : bool, optional
+            Copy the data if true, otherwise create a view (default).
+        order : string, optional
+            F order (default) or C. C is faster with external libraries.
+
+        Returns
+        -------
+        list of cupy.array
+            A list of cupy n-dimensional arrays, for each local block in the
+            MultiFab.
+
+        Raises
+        ------
+        ImportError
+            Raises an exception if cupy is not installed
+
+        """
+    def to_numpy(self, copy=False, order="F"):
+        """
+
+        Provide a Numpy view into a MultiFab.
+
+        Note on the order of indices:
+        By default, this is as in AMReX in Fortran contiguous order, indexing as
+        x,y,z. This has performance implications for use in external libraries such
+        as cupy.
+        The order="C" option will index as z,y,x and perform better with cupy.
+        https://github.com/AMReX-Codes/pyamrex/issues/55#issuecomment-1579610074
+
+        Parameters
+        ----------
+        self : amrex.MultiFab
+            A MultiFab class in pyAMReX
+        copy : bool, optional
+            Copy the data if true, otherwise create a view (default).
+        order : string, optional
+            F order (default) or C. C is faster with external libraries.
+
+        Returns
+        -------
+        list of numpy.array
+            A list of numpy n-dimensional arrays, for each local block in the
+            MultiFab.
+
+        """
     def weighted_sync(self, arg0: MultiFab, arg1: Periodicity) -> None: ...
 
 class PIdx:

src/amrex/space2d/__init__.py

@@ -46,10 +46,12 @@ def Print(*args, **kwargs):
 
 from ..Array4 import register_Array4_extension
 from ..ArrayOfStructs import register_AoS_extension
+from ..MultiFab import register_MultiFab_extension
 from ..PODVector import register_PODVector_extension
 from ..StructOfArrays import register_SoA_extension
 
 register_Array4_extension(amrex_2d_pybind)
+register_MultiFab_extension(amrex_2d_pybind)
 register_PODVector_extension(amrex_2d_pybind)
 register_SoA_extension(amrex_2d_pybind)
 register_AoS_extension(amrex_2d_pybind)

src/amrex/space2d/__init__.pyi

@@ -38,6 +38,7 @@ import os as os
 
 from amrex.Array4 import register_Array4_extension
 from amrex.ArrayOfStructs import register_AoS_extension
+from amrex.MultiFab import register_MultiFab_extension
 from amrex.PODVector import register_PODVector_extension
 from amrex.StructOfArrays import register_SoA_extension
 from amrex.space2d.amrex_2d_pybind import (
@@ -461,6 +462,7 @@ __all__ = [
     "refine",
     "register_AoS_extension",
     "register_Array4_extension",
+    "register_MultiFab_extension",
     "register_PODVector_extension",
     "register_SoA_extension",
     "size",

src/amrex/space2d/amrex_2d_pybind/__init__.pyi

@@ -4049,6 +4049,67 @@ class MultiFab(FabArray_FArrayBox):
         """
         Same as sum with local=false, but for non-cell-centered data, thisskips non-unique points that are owned by multiple boxes.
         """
+    def to_cupy(self, copy=False, order="F"):
+        """
+
+        Provide a Cupy view into a MultiFab.
+
+        Note on the order of indices:
+        By default, this is as in AMReX in Fortran contiguous order, indexing as
+        x,y,z. This has performance implications for use in external libraries such
+        as cupy.
+        The order="C" option will index as z,y,x and perform better with cupy.
+        https://github.com/AMReX-Codes/pyamrex/issues/55#issuecomment-1579610074
+
+        Parameters
+        ----------
+        self : amrex.MultiFab
+            A MultiFab class in pyAMReX
+        copy : bool, optional
+            Copy the data if true, otherwise create a view (default).
+        order : string, optional
+            F order (default) or C. C is faster with external libraries.
+
+        Returns
+        -------
+        list of cupy.array
+            A list of cupy n-dimensional arrays, for each local block in the
+            MultiFab.
+
+        Raises
+        ------
+        ImportError
+            Raises an exception if cupy is not installed
+
+        """
+    def to_numpy(self, copy=False, order="F"):
+        """
+
+        Provide a Numpy view into a MultiFab.
+
+        Note on the order of indices:
+        By default, this is as in AMReX in Fortran contiguous order, indexing as
+        x,y,z. This has performance implications for use in external libraries such
+        as cupy.
+        The order="C" option will index as z,y,x and perform better with cupy.
+        https://github.com/AMReX-Codes/pyamrex/issues/55#issuecomment-1579610074
+
+        Parameters
+        ----------
+        self : amrex.MultiFab
+            A MultiFab class in pyAMReX
+        copy : bool, optional
+            Copy the data if true, otherwise create a view (default).
+        order : string, optional
+            F order (default) or C. C is faster with external libraries.
+
+        Returns
+        -------
+        list of numpy.array
+            A list of numpy n-dimensional arrays, for each local block in the
+            MultiFab.
+
+        """
     def weighted_sync(self, arg0: MultiFab, arg1: Periodicity) -> None: ...
 
 class PIdx:

src/amrex/space3d/__init__.py

@@ -46,10 +46,12 @@ def Print(*args, **kwargs):
 
 from ..Array4 import register_Array4_extension
 from ..ArrayOfStructs import register_AoS_extension
+from ..MultiFab import register_MultiFab_extension
 from ..PODVector import register_PODVector_extension
 from ..StructOfArrays import register_SoA_extension
 
 register_Array4_extension(amrex_3d_pybind)
+register_MultiFab_extension(amrex_3d_pybind)
 register_PODVector_extension(amrex_3d_pybind)
 register_SoA_extension(amrex_3d_pybind)
 register_AoS_extension(amrex_3d_pybind)

src/amrex/space3d/__init__.pyi

@@ -38,6 +38,7 @@ import os as os
 
 from amrex.Array4 import register_Array4_extension
 from amrex.ArrayOfStructs import register_AoS_extension
+from amrex.MultiFab import register_MultiFab_extension
 from amrex.PODVector import register_PODVector_extension
 from amrex.StructOfArrays import register_SoA_extension
 from amrex.space3d.amrex_3d_pybind import (
@@ -461,6 +462,7 @@ __all__ = [
     "refine",
     "register_AoS_extension",
     "register_Array4_extension",
+    "register_MultiFab_extension",
     "register_PODVector_extension",
     "register_SoA_extension",
     "size",

src/amrex/space3d/amrex_3d_pybind/__init__.pyi

@@ -4052,6 +4052,67 @@ class MultiFab(FabArray_FArrayBox):
         """
         Same as sum with local=false, but for non-cell-centered data, thisskips non-unique points that are owned by multiple boxes.
         """
+    def to_cupy(self, copy=False, order="F"):
+        """
+
+        Provide a Cupy view into a MultiFab.
+
+        Note on the order of indices:
+        By default, this is as in AMReX in Fortran contiguous order, indexing as
+        x,y,z. This has performance implications for use in external libraries such
+        as cupy.
+        The order="C" option will index as z,y,x and perform better with cupy.
+        https://github.com/AMReX-Codes/pyamrex/issues/55#issuecomment-1579610074
+
+        Parameters
+        ----------
+        self : amrex.MultiFab
+            A MultiFab class in pyAMReX
+        copy : bool, optional
+            Copy the data if true, otherwise create a view (default).
+        order : string, optional
+            F order (default) or C. C is faster with external libraries.
+
+        Returns
+        -------
+        list of cupy.array
+            A list of cupy n-dimensional arrays, for each local block in the
+            MultiFab.
+
+        Raises
+        ------
+        ImportError
+            Raises an exception if cupy is not installed
+
+        """
+    def to_numpy(self, copy=False, order="F"):
+        """
+
+        Provide a Numpy view into a MultiFab.
+
+        Note on the order of indices:
+        By default, this is as in AMReX in Fortran contiguous order, indexing as
+        x,y,z. This has performance implications for use in external libraries such
+        as cupy.
+        The order="C" option will index as z,y,x and perform better with cupy.
+        https://github.com/AMReX-Codes/pyamrex/issues/55#issuecomment-1579610074
+
+        Parameters
+        ----------
+        self : amrex.MultiFab
+            A MultiFab class in pyAMReX
+        copy : bool, optional
+            Copy the data if true, otherwise create a view (default).
+        order : string, optional
+            F order (default) or C. C is faster with external libraries.
+
+        Returns
+        -------
+        list of numpy.array
+            A list of numpy n-dimensional arrays, for each local block in the
+            MultiFab.
+
+        """
     def weighted_sync(self, arg0: MultiFab, arg1: Periodicity) -> None: ...
 
 class PIdx:

tests/test_multifab.py

@@ -350,3 +350,13 @@ def test_mfab_dtoh_copy(make_mfab_device):
     device_max = mfab_device.max(0)
     assert device_min == device_max
     assert device_max == 11.0
+
+    # numpy bindings (w/ copy)
+    local_boxes_host = mfab_device.to_numpy(copy=True)
+    assert max([np.max(box) for box in local_boxes_host]) == device_max
+
+    # cupy bindings (w/o copy)
+    import cupy as cp
+
+    local_boxes_device = mfab_device.to_cupy()
+    assert max([cp.max(box) for box in local_boxes_device]) == device_max