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Diffstat (limited to 'doc/CAPI.txt')
| -rw-r--r-- | doc/CAPI.txt | 105 |
1 files changed, 66 insertions, 39 deletions
diff --git a/doc/CAPI.txt b/doc/CAPI.txt index be6c50d94..1b31e3e94 100644 --- a/doc/CAPI.txt +++ b/doc/CAPI.txt @@ -4,21 +4,24 @@ The CAPI of SciPy is (mostly) backward compatible with Numeric. There are a few non-standard API Numeric usages that will need to be changed: * If you used any of the function pointers in the PyArray_Descr - structure you will have to modify your usage of those. The casting functions - have eliminated the strides argument (use PyArray_CastTo if you need strided casting). - All functions have one or two PyArrayObject * arguments at the end. This allows - the flexible arrays and mis-behaved arrays to be handled. + structure you will have to modify your usage of those. The + casting functions have eliminated the strides argument (use + PyArray_CastTo if you need strided casting). All functions have + one or two PyArrayObject * arguments at the end. This allows the + flexible arrays and mis-behaved arrays to be handled. * The descr->zero and descr->one constants have been replaced with function calls, PyArray_Zero, and PyArray_One. - * You should use PyArray_ITEMSIZE(obj) instead of descr->elsize to get the itemsize of an - object (for flexible arrays descr->elsize is 0). + * You should use PyArray_ITEMSIZE(obj) instead of descr->elsize to + get the itemsize of an object (for flexible arrays descr->elsize + is 0). The header files arrayobject.h and ufuncobject.h contain many defines that you may find useful. The files __ufunc_api.h and -__multiarray_api.h contain the available C-API function calls with their function signatures. +__multiarray_api.h contain the available C-API function calls with +their function signatures. All of these headers are installed to @@ -37,44 +40,62 @@ PyObject * PyArray_New(PyTypeObject *subtype, int nd, intp *dims, int type, PyObject *obj); -subtype : The subtype that should be created (either pass in - &PyArray_Type, &PyBigArray_Type, or obj->ob_type, - where obj is a subtype (or subclass) of PyBigArray_Type). +subtype : The subtype that should be created (either pass in + &PyArray_Type, &PyBigArray_Type, or obj->ob_type, + where obj is a subtype (or subclass) of PyBigArray_Type). nd : The number of dimensions (<MAX_DIMS) -*dims : A pointer to the size in each dimension. Information will be copied from here. + +*dims : A pointer to the size in each dimension. Information will be + copied from here. + type : An integer specifying the type of the array. -*strides : The strides this array should have. For new arrays created by this routine, this - should be NULL. If you pass in memory for this array to use, then you should pass - in the strides information as well. I -*data : NULL for creating brand-new memory. If you want this array to wrap another memory - area, then pass the pointer here. You are responsible for deleting the memory in that - case, but do not do so until the new array object has been deleted. The best way to - handle that is to get the memory from another Python object, - INCREF that Python object after passing it's data pointer to this routine, and - set the ->base member of the returned array to the Python object. You are - responsible for setting the base object. Failure to do so will create a memory leak. + +*strides : The strides this array should have. For new arrays created + by this routine, this should be NULL. If you pass in + memory for this array to use, then you should pass in the + strides information as well. I + +*data : NULL for creating brand-new memory. If you want this array + to wrap another memory area, then pass the pointer here. + You are responsible for deleting the memory in that case, + but do not do so until the new array object has been + deleted. The best way to handle that is to get the memory + from another Python object, INCREF that Python object after + passing it's data pointer to this routine, and set the + ->base member of the returned array to the Python object. + You are responsible for setting the base object. Failure + to do so will create a memory leak. - If you pass in a data buffer, the flags argument will be the flags of the new array. - If you create a new array, a non-zero flags argument indicates that you want the - array to be in FORTRAN order. + If you pass in a data buffer, the flags argument will be + the flags of the new array. If you create a new array, a + non-zero flags argument indicates that you want the array + to be in FORTRAN order. + + +itemsize : Indicates the itemsize for the new array. This can be 0 + if it is a fixed-size array type. It is only used for + flexible array types and must be set in that case. -itemsize : Indicates the itemsize for the new array. This can be 0 if it is a fixed-size array type. - It is only used for flexible array types and must be set in that case. -flags : Either the flags showing how to interpret the data buffer passed in. Or if a new array - is created, nonzero to indicate a FORTRAN order array. +flags : Either the flags showing how to interpret the data buffer + passed in. Or if a new array is created, nonzero to + indicate a FORTRAN order array. -obj : If subtypes is &PyArray_Type or &PyBigArray_Type, this argument is ignored. Otherwise, - the __array_finalize__ method of the subtype is called (if present) and passed this - object. This is usually an array of the type to be created (so the __array_finalize__ - method must handle an array argument. But, it can be anything...) -Note: The returned array object will be unitialized unless the type is PyArray_OBJECT. +obj : If subtypes is &PyArray_Type or &PyBigArray_Type, this + argument is ignored. Otherwise, the __array_finalize__ + method of the subtype is called (if present) and passed + this object. This is usually an array of the type to be + created (so the __array_finalize__ method must handle an + array argument. But, it can be anything...) +Note: The returned array object will be unitialized unless the type is +PyArray_OBJECT. -The PyArray_FromDims and family of functions are still available and are loose wrappers around -this function. + +The PyArray_FromDims and family of functions are still available and +are loose wrappers around this function. Getting an arrayobject from an arbitrary Python object: PyArray_FromAny @@ -89,12 +110,18 @@ PyArray_FromAny(PyObject *op, PyArray_Typecode *typecode, int min_depth, op : The Python object to "convert" to an array object -typecode : A typecode structure filled with the data type and itemsize of the desired data type. - This can be NULL, if the type should be determined from the object. - Unless FORCECAST is present in flags, this call will generate an error - if the data type cannot be safely obtained from the object. + +typecode : A typecode structure filled with the data type and + itemsize of the desired data type. This can be NULL, if + the type should be determined from the object. Unless + FORCECAST is present in flags, this call will generate + an error if the data type cannot be safely obtained from + the object. + min_depth : The minimum depth of array needed or 0 if doesn't matter + max_depth : The maximum depth of array allowed or 0 if doesn't matter + requires : A flag indicating the "requirements" of the returned array. |