xref: /libCEED/python/ceed_qfunction.py (revision ddb811d62b4892d33efe74864db9a98287f88a1a)
1# Copyright (c) 2017, Lawrence Livermore National Security, LLC. Produced at
2# the Lawrence Livermore National Laboratory. LLNL-CODE-734707. All Rights
3# reserved. See files LICENSE and NOTICE for details.
4#
5# This file is part of CEED, a collection of benchmarks, miniapps, software
6# libraries and APIs for efficient high-order finite element and spectral
7# element discretizations for exascale applications. For more information and
8# source code availability see http://github.com/ceed.
9#
10# The CEED research is supported by the Exascale Computing Project 17-SC-20-SC,
11# a collaborative effort of two U.S. Department of Energy organizations (Office
12# of Science and the National Nuclear Security Administration) responsible for
13# the planning and preparation of a capable exascale ecosystem, including
14# software, applications, hardware, advanced system engineering and early
15# testbed platforms, in support of the nation's exascale computing imperative.
16
17from _ceed_cffi import ffi, lib
18import ctypes
19import tempfile
20from abc import ABC
21
22# ------------------------------------------------------------------------------
23
24
25class _QFunctionBase(ABC):
26    """Ceed QFunction: point-wise operation at quadrature points for evaluating
27         volumetric terms."""
28
29    # Attributes
30    _ceed = None
31    _pointer = ffi.NULL
32
33    # Destructor
34    def __del__(self):
35        # libCEED call
36        err_code = lib.CeedQFunctionDestroy(self._pointer)
37        self._ceed._check_error(err_code)
38
39    # Representation
40    def __repr__(self):
41        return "<CeedQFunction instance at " + hex(id(self)) + ">"
42
43    # String conversion for print() to stdout
44    def __str__(self):
45        """View a QFunction via print()."""
46
47        # libCEED call
48        with tempfile.NamedTemporaryFile() as key_file:
49            with open(key_file.name, 'r+') as stream_file:
50                stream = ffi.cast("FILE *", stream_file)
51
52                err_code = lib.CeedQFunctionView(self._pointer[0], stream)
53                self._ceed._check_error(err_code)
54
55                stream_file.seek(0)
56                out_string = stream_file.read()
57
58        return out_string
59
60    # Apply CeedQFunction
61    def apply(self, q, inputs, outputs):
62        """Apply the action of a QFunction.
63
64           Args:
65             q: number of quadrature points
66             *inputs: array of input data vectors
67             *outputs: array of output data vectors"""
68
69        # Array of vectors
70        invecs = ffi.new("CeedVector[16]")
71        for i in range(min(16, len(inputs))):
72            invecs[i] = inputs[i]._pointer[0]
73        outvecs = ffi.new("CeedVector[16]")
74        for i in range(min(16, len(outputs))):
75            outvecs[i] = outputs[i]._pointer[0]
76
77        # libCEED call
78        err_code = lib.CeedQFunctionApply(self._pointer[0], q, invecs, outvecs)
79        self._ceed._check_error(err_code)
80
81        # Clean-up
82        ffi.release(invecs)
83        ffi.release(outvecs)
84
85
86# ------------------------------------------------------------------------------
87class QFunction(_QFunctionBase):
88    """Ceed QFunction: point-wise operation at quadrature points for evaluating
89         volumetric terms."""
90
91    # Constructor
92    def __init__(self, ceed, vlength, f, source):
93        # libCEED object
94        self._pointer = ffi.new("CeedQFunction *")
95
96        # Reference to Ceed
97        self._ceed = ceed
98
99        # Function pointer
100        fpointer = ffi.cast(
101            "CeedQFunctionUser", ctypes.cast(
102                f, ctypes.c_void_p).value)
103
104        # libCEED call
105        sourceAscii = ffi.new("char[]", source.encode('ascii'))
106        err_code = lib.CeedQFunctionCreateInterior(self._ceed._pointer[0], vlength,
107                                                   fpointer, sourceAscii, self._pointer)
108        self._ceed._check_error(err_code)
109
110    # Set context data
111    def set_context(self, ctx):
112        """Set global context for a QFunction.
113
114           Args:
115             ctx: Ceed User Context object holding context data"""
116
117        # libCEED call
118        err_code = lib.CeedQFunctionSetContext(
119            self._pointer[0],
120            ctx._pointer[0])
121        self._ceed._check_error(err_code)
122
123    # Add fields to CeedQFunction
124    def add_input(self, fieldname, size, emode):
125        """Add a QFunction input.
126
127           Args:
128             fieldname: name of QFunction field
129             size: size of QFunction field, (ncomp * dim) for CEED_EVAL_GRAD or
130                     (ncomp * 1) for CEED_EVAL_NONE and CEED_EVAL_INTERP
131             **emode: CEED_EVAL_NONE to use values directly,
132                      CEED_EVAL_INTERP to use interpolated values,
133                      CEED_EVAL_GRAD to use gradients."""
134
135        # libCEED call
136        fieldnameAscii = ffi.new("char[]", fieldname.encode('ascii'))
137        err_code = lib.CeedQFunctionAddInput(
138            self._pointer[0], fieldnameAscii, size, emode)
139        self._ceed._check_error(err_code)
140
141    def add_output(self, fieldname, size, emode):
142        """Add a QFunction output.
143
144           Args:
145             fieldname: name of QFunction field
146             size: size of QFunction field, (ncomp * dim) for CEED_EVAL_GRAD or
147                     (ncomp * 1) for CEED_EVAL_NONE and CEED_EVAL_INTERP
148             **emode: CEED_EVAL_NONE to use values directly,
149                      CEED_EVAL_INTERP to use interpolated values,
150                      CEED_EVAL_GRAD to use gradients."""
151
152        # libCEED call
153        fieldnameAscii = ffi.new("char[]", fieldname.encode('ascii'))
154        err_code = lib.CeedQFunctionAddOutput(
155            self._pointer[0], fieldnameAscii, size, emode)
156        self._ceed._check_error(err_code)
157
158# ------------------------------------------------------------------------------
159
160
161class QFunctionByName(_QFunctionBase):
162    """Ceed QFunction By Name: point-wise operation at quadrature points
163         from a given gallery, for evaluating volumetric terms."""
164
165    # Constructor
166    def __init__(self, ceed, name):
167        # libCEED object
168        self._pointer = ffi.new("CeedQFunction *")
169
170        # Reference to Ceed
171        self._ceed = ceed
172
173        # libCEED call
174        nameAscii = ffi.new("char[]", name.encode('ascii'))
175        err_code = lib.CeedQFunctionCreateInteriorByName(self._ceed._pointer[0],
176                                                         nameAscii, self._pointer)
177        self._ceed._check_error(err_code)
178
179# ------------------------------------------------------------------------------
180
181
182class IdentityQFunction(_QFunctionBase):
183    """Ceed Identity QFunction: identity qfunction operation."""
184
185    # Constructor
186    def __init__(self, ceed, size, inmode, outmode):
187        # libCEED object
188        self._pointer = ffi.new("CeedQFunction *")
189
190        # Reference to Ceed
191        self._ceed = ceed
192
193        # libCEED call
194        err_code = lib.CeedQFunctionCreateIdentity(self._ceed._pointer[0], size,
195                                                   inmode, outmode, self._pointer)
196
197# ------------------------------------------------------------------------------
198