diff options
Diffstat (limited to 'doc/source')
| -rw-r--r-- | doc/source/user/c-info.ufunc-tutorial.rst | 298 |
1 files changed, 144 insertions, 154 deletions
diff --git a/doc/source/user/c-info.ufunc-tutorial.rst b/doc/source/user/c-info.ufunc-tutorial.rst index d1d344099..f1adef59a 100644 --- a/doc/source/user/c-info.ufunc-tutorial.rst +++ b/doc/source/user/c-info.ufunc-tutorial.rst @@ -84,42 +84,46 @@ the module. #include <math.h> /* - spammodule.c - This is the C code for a non-numpy Python extension to - define the logit function, where logit(p) = log(p/(1-p)). - This function will not work on numpy arrays automatically. - numpy.vectorize must be called in python to generate - a numpy-friendly function. - - Details explaining the Python-C API can be found under - 'Extending and Embedding' and 'Python/C API' at - docs.python.org . - */ + * spammodule.c + * This is the C code for a non-numpy Python extension to + * define the logit function, where logit(p) = log(p/(1-p)). + * This function will not work on numpy arrays automatically. + * numpy.vectorize must be called in python to generate + * a numpy-friendly function. + * + * Details explaining the Python-C API can be found under + * 'Extending and Embedding' and 'Python/C API' at + * docs.python.org . + */ /* This declares the logit function */ static PyObject* spam_logit(PyObject *self, PyObject *args); - /* This tells Python what methods this module has */ + /* + * This tells Python what methods this module has. + * See the Python-C API for more information. + */ static PyMethodDef SpamMethods[] = { - {"logit", spam_logit, METH_VARARGS, - "compute logit"}, + {"logit", + spam_logit, + METH_VARARGS, "compute logit"}, {NULL, NULL, 0, NULL} }; /* - This actually defines the logit function for - input args from Python. - */ - - static PyObject* spam_logit(PyObject *self, PyObject *args){ + * This actually defines the logit function for + * input args from Python. + */ + static PyObject* spam_logit(PyObject *self, PyObject *args) + { double p; /* This parses the Python argument into a double */ - if(!PyArg_ParseTuple(args, "d", &p)){ + if(!PyArg_ParseTuple(args, "d", &p)) { return NULL; } @@ -133,14 +137,14 @@ the module. /* This initiates the module using the above definitions. */ - PyMODINIT_FUNC initspam(void){ + PyMODINIT_FUNC initspam(void) + { PyObject *m; m = Py_InitModule("spam", SpamMethods); - if( m==NULL){ + if (m == NULL) { return; } - } To use the setup.py file, place setup.py and spammodule.c in the same @@ -224,39 +228,39 @@ the primary thing that must be changed to create your own ufunc. #include "numpy/halffloat.h" /* - single_type_logit.c - This is the C code for creating your own - Numpy ufunc for a logit function. - - In this code we only define the ufunc for - a single dtype. The computations that must - be replaced to create a ufunc for - a different funciton are marked with BEGIN - and END. - - Details explaining the Python-C API can be found under - 'Extending and Embedding' and 'Python/C API' at - docs.python.org . - - */ + * single_type_logit.c + * This is the C code for creating your own + * Numpy ufunc for a logit function. + * + * In this code we only define the ufunc for + * a single dtype. The computations that must + * be replaced to create a ufunc for + * a different funciton are marked with BEGIN + * and END. + * + * Details explaining the Python-C API can be found under + * 'Extending and Embedding' and 'Python/C API' at + * docs.python.org . + */ static PyMethodDef LogitMethods[] = { {NULL, NULL, 0, NULL} }; + /* The loop definition must precede the PyMODINIT_FUNC. */ static void double_logit(char **args, npy_intp *dimensions, - npy_intp* steps, void* data){ - + npy_intp* steps, void* data) + { npy_intp i; - npy_intp n=dimensions[0]; - char *in=args[0], *out=args[1]; - npy_intp in_step=steps[0], out_step=steps[1]; + npy_intp n = dimensions[0]; + char *in = args[0], *out = args[1]; + npy_intp in_step = steps[0], out_step = steps[1]; double tmp; - for(i=0; i<n; i++){ + for (i = 0; i < n; i++) { /*BEGIN main ufunc computation*/ tmp = *(double *)in; tmp /= 1-tmp; @@ -268,30 +272,23 @@ the primary thing that must be changed to create your own ufunc. } } - - /* - These definitions must be outside PyMODINIT_FUNC. - They must be global, but will be local if declared - inside PyMODINIT_FUNC. - */ - - /*This a pointer to the above function*/ PyUFuncGenericFunction funcs[1] = {&double_logit}; /* These are the input and return dtypes of logit.*/ - char types[2] = {NPY_DOUBLE,NPY_DOUBLE}; + char types[2] = {NPY_DOUBLE, NPY_DOUBLE}; void *data[1] = {NULL}; - PyMODINIT_FUNC initnpspam(void){ + PyMODINIT_FUNC initnpspam(void) + { PyObject *m, *logit, *d; - m =Py_InitModule("npspam", LogitMethods); - if( m==NULL ){ + m = Py_InitModule("npspam", LogitMethods); + if (m == NULL) { return; } @@ -299,12 +296,12 @@ the primary thing that must be changed to create your own ufunc. import_umath(); logit = PyUFunc_FromFuncAndData(funcs,data, types, 1, 1, 1, - PyUFunc_None, "logit", - "logit_docstring", 0); + PyUFunc_None, "logit", + "logit_docstring", 0); d = PyModule_GetDict(m); - PyDict_SetItemString(d , "logit", logit); + PyDict_SetItemString(d, "logit", logit); Py_DECREF(logit); } @@ -391,41 +388,42 @@ the primary thing that must be changed to create your own ufunc. #include "numpy/halffloat.h" /* - multi_type_logit.c - This is the C code for creating your own - Numpy ufunc for a logit function. - - Each function of the form type_logit defines the - logit function for a different numpy dtype. Each - of these functions must be modified when you - create your own ufunc. The computations that must - be replaced to create a ufunc for - a different funciton are marked with BEGIN - and END. - - Details explaining the Python-C API can be found under - 'Extending and Embedding' and 'Python/C API' at - docs.python.org . - - */ + * multi_type_logit.c + * This is the C code for creating your own + * Numpy ufunc for a logit function. + * + * Each function of the form type_logit defines the + * logit function for a different numpy dtype. Each + * of these functions must be modified when you + * create your own ufunc. The computations that must + * be replaced to create a ufunc for + * a different funciton are marked with BEGIN + * and END. + * + * Details explaining the Python-C API can be found under + * 'Extending and Embedding' and 'Python/C API' at + * docs.python.org . + * + */ static PyMethodDef LogitMethods[] = { {NULL, NULL, 0, NULL} }; + /* The loop definitions must precede the PyMODINIT_FUNC. */ static void long_double_logit(char **args, npy_intp *dimensions, - npy_intp* steps, void* data){ - + npy_intp* steps, void* data) + { npy_intp i; - npy_intp n=dimensions[0]; - char *in=args[0], *out=args[1]; - npy_intp in_step=steps[0], out_step=steps[1]; + npy_intp n = dimensions[0]; + char *in = args[0], *out=args[1]; + npy_intp in_step = steps[0], out_step = steps[1]; long double tmp; - for(i=0; i<n; i++){ + for (i = 0; i < n; i++) { /*BEGIN main ufunc computation*/ tmp = *(long double *)in; tmp /= 1-tmp; @@ -438,16 +436,16 @@ the primary thing that must be changed to create your own ufunc. } static void double_logit(char **args, npy_intp *dimensions, - npy_intp* steps, void* data){ - + npy_intp* steps, void* data) + { npy_intp i; - npy_intp n=dimensions[0]; - char *in=args[0], *out=args[1]; - npy_intp in_step=steps[0], out_step=steps[1]; + npy_intp n = dimensions[0]; + char *in = args[0], *out = args[1]; + npy_intp in_step = steps[0], out_step = steps[1]; double tmp; - for(i=0; i<n; i++){ + for (i = 0; i < n; i++) { /*BEGIN main ufunc computation*/ tmp = *(double *)in; tmp /= 1-tmp; @@ -460,16 +458,16 @@ the primary thing that must be changed to create your own ufunc. } static void float_logit(char **args, npy_intp *dimensions, - npy_intp* steps, void* data){ - + npy_intp* steps, void* data) + { npy_intp i; - npy_intp n=dimensions[0]; - char *in=args[0], *out=args[1]; - npy_intp in_step=steps[0], out_step=steps[1]; + npy_intp n = dimensions[0]; + char *in=args[0], *out = args[1]; + npy_intp in_step = steps[0], out_step = steps[1]; float tmp; - for(i=0; i<n; i++){ + for (i = 0; i < n; i++) { /*BEGIN main ufunc computation*/ tmp = *(float *)in; tmp /= 1-tmp; @@ -483,16 +481,16 @@ the primary thing that must be changed to create your own ufunc. static void half_float_logit(char **args, npy_intp *dimensions, - npy_intp* steps, void* data){ - + npy_intp* steps, void* data) + { npy_intp i; - npy_intp n=dimensions[0]; - char *in=args[0], *out=args[1]; - npy_intp in_step=steps[0], out_step=steps[1]; + npy_intp n = dimensions[0]; + char *in = args[0], *out = args[1]; + npy_intp in_step = steps[0], out_step = steps[1]; float tmp; - for(i=0; i<n; i++){ + for (i = 0; i < n; i++) { /*BEGIN main ufunc computation*/ tmp = *(npy_half *)in; @@ -507,23 +505,17 @@ the primary thing that must be changed to create your own ufunc. } } - /* - These definitions must be outside PyMODINIT_FUNC. - They must be global, but will be local if declared - inside PyMODINIT_FUNC. - */ - /*This gives pointers to the above functions*/ - PyUFuncGenericFunction funcs[4] = {&half_float_logit, &float_logit, - &double_logit, &long_double_logit}; + PyUFuncGenericFunction funcs[4] = {&half_float_logit, + &float_logit, + &double_logit, + &long_double_logit}; - /* - These are the input and return dtypes of logit. They must - be in the same order as the funcs array immediately above. - */ - char types[8] = {NPY_HALF, NPY_HALF, NPY_FLOAT, NPY_FLOAT, - NPY_DOUBLE,NPY_DOUBLE, NPY_LONGDOUBLE, NPY_LONGDOUBLE}; + char types[8] = {NPY_HALF, NPY_HALF, + NPY_FLOAT, NPY_FLOAT, + NPY_DOUBLE,NPY_DOUBLE, + NPY_LONGDOUBLE, NPY_LONGDOUBLE}; void *data[4] = {NULL, NULL, NULL, NULL}; @@ -532,8 +524,8 @@ the primary thing that must be changed to create your own ufunc. PyObject *m, *logit, *d; - m =Py_InitModule("npspam", LogitMethods); - if( m==NULL ){ + m = Py_InitModule("npspam", LogitMethods); + if (m == NULL) { return; } @@ -541,12 +533,12 @@ the primary thing that must be changed to create your own ufunc. import_umath(); logit = PyUFunc_FromFuncAndData(funcs,data, types, 4, 1, 1, - PyUFunc_None, "logit", - "logit_docstring", 0); + PyUFunc_None, "logit", + "logit_docstring", 0); d = PyModule_GetDict(m); - PyDict_SetItemString(d , "logit", logit); + PyDict_SetItemString(d, "logit", logit); Py_DECREF(logit); } @@ -588,8 +580,12 @@ or installed to site-packages via python setup.py install. #Necessary for the half-float d-type. info = get_info('npymath') - config = Configuration('npspam_directory', parent_package, top_path) - config.add_extension('npspam', ['multi_type_logit.c'], extra_info=info) + config = Configuration('npspam_directory', + parent_package, + top_path) + config.add_extension('npspam', + ['multi_type_logit.c'], + extra_info=info) return config @@ -646,38 +642,39 @@ as well as all other properties of a ufunc. #include "numpy/halffloat.h" /* - multi_arg_logit.c - This is the C code for creating your own - Numpy ufunc for a multiple argument, multiple - return value ufunc. The places where the - ufunc computation is carried out are marked - with comments. - - Details explaining the Python-C API can be found under - 'Extending and Embedding' and 'Python/C API' at - docs.python.org . - - */ + * multi_arg_logit.c + * This is the C code for creating your own + * Numpy ufunc for a multiple argument, multiple + * return value ufunc. The places where the + * ufunc computation is carried out are marked + * with comments. + * + * Details explaining the Python-C API can be found under + * 'Extending and Embedding' and 'Python/C API' at + * docs.python.org . + * + */ static PyMethodDef LogitMethods[] = { {NULL, NULL, 0, NULL} }; + /* The loop definition must precede the PyMODINIT_FUNC. */ static void double_logitprod(char **args, npy_intp *dimensions, - npy_intp* steps, void* data){ - + npy_intp* steps, void* data) + { npy_intp i; - npy_intp n=dimensions[0]; - char *in1=args[0], *in2=args[1]; - char *out1=args[2], *out2=args[3]; - npy_intp in1_step=steps[0], in2_step=steps[1]; - npy_intp out1_step=steps[2], out2_step=steps[3]; + npy_intp n = dimensions[0]; + char *in1 = args[0], *in2 = args[1]; + char *out1 = args[2], *out2 = args[3]; + npy_intp in1_step = steps[0], in2_step = steps[1]; + npy_intp out1_step = steps[2], out2_step = steps[3]; double tmp; - for(i=0; i<n; i++){ + for (i = 0; i < n; i++) { /*BEGIN main ufunc computation*/ tmp = *(double *)in1; tmp *= *(double *)in2; @@ -693,19 +690,12 @@ as well as all other properties of a ufunc. } - /* - These definitions must be outside PyMODINIT_FUNC. - They must be global, but will be local if declared - inside PyMODINIT_FUNC. - */ - - /*This a pointer to the above function*/ PyUFuncGenericFunction funcs[1] = {&double_logitprod}; /* These are the input and return dtypes of logit.*/ - char types[4] = {NPY_DOUBLE,NPY_DOUBLE, NPY_DOUBLE, NPY_DOUBLE}; + char types[4] = {NPY_DOUBLE, NPY_DOUBLE, NPY_DOUBLE, NPY_DOUBLE}; void *data[1] = {NULL}; @@ -714,8 +704,8 @@ as well as all other properties of a ufunc. PyObject *m, *logitprod, *d; - m =Py_InitModule("npspam", LogitMethods); - if( m==NULL ){ + m = Py_InitModule("npspam", LogitMethods); + if (m == NULL) { return; } @@ -723,12 +713,12 @@ as well as all other properties of a ufunc. import_umath(); logitprod = PyUFunc_FromFuncAndData(funcs,data, types, 1, 2, 2, - PyUFunc_None, "logitprod", - "logitprod_docstring", 0); + PyUFunc_None, "logitprod", + "logitprod_docstring", 0); d = PyModule_GetDict(m); - PyDict_SetItemString(d , "logitprod", logitprod); + PyDict_SetItemString(d, "logitprod", logitprod); Py_DECREF(logitprod); } |