Ejemplo n.º 1
0
/*
 * optimize float array or complex array to a scalar power
 * returns 0 on success, -1 if no optimization is possible
 * the result is in value (can be NULL if an error occurred)
 */
static int
fast_scalar_power(PyArrayObject *a1, PyObject *o2, int inplace,
                  PyObject **value)
{
    double exponent;
    NPY_SCALARKIND kind;   /* NPY_NOSCALAR is not scalar */

    if (PyArray_Check(a1) &&
            !PyArray_ISOBJECT(a1) &&
            ((kind=is_scalar_with_conversion(o2, &exponent))>0)) {
        PyObject *fastop = NULL;
        if (PyArray_ISFLOAT(a1) || PyArray_ISCOMPLEX(a1)) {
            if (exponent == 1.0) {
                fastop = n_ops.positive;
            }
            else if (exponent == -1.0) {
                fastop = n_ops.reciprocal;
            }
            else if (exponent ==  0.0) {
                fastop = n_ops._ones_like;
            }
            else if (exponent ==  0.5) {
                fastop = n_ops.sqrt;
            }
            else if (exponent ==  2.0) {
                fastop = n_ops.square;
            }
            else {
                return -1;
            }

            if (inplace || can_elide_temp_unary(a1)) {
                *value = PyArray_GenericInplaceUnaryFunction(a1, fastop);
            }
            else {
                *value = PyArray_GenericUnaryFunction(a1, fastop);
            }
            return 0;
        }
        /* Because this is called with all arrays, we need to
         *  change the output if the kind of the scalar is different
         *  than that of the input and inplace is not on ---
         *  (thus, the input should be up-cast)
         */
        else if (exponent == 2.0) {
            fastop = n_ops.square;
            if (inplace) {
                *value = PyArray_GenericInplaceUnaryFunction(a1, fastop);
            }
            else {
                /* We only special-case the FLOAT_SCALAR and integer types */
                if (kind == NPY_FLOAT_SCALAR && PyArray_ISINTEGER(a1)) {
                    PyArray_Descr *dtype = PyArray_DescrFromType(NPY_DOUBLE);
                    a1 = (PyArrayObject *)PyArray_CastToType(a1, dtype,
                            PyArray_ISFORTRAN(a1));
                    if (a1 != NULL) {
                        /* cast always creates a new array */
                        *value = PyArray_GenericInplaceUnaryFunction(a1, fastop);
                        Py_DECREF(a1);
                    }
                }
                else {
                    *value = PyArray_GenericUnaryFunction(a1, fastop);
                }
            }
            return 0;
        }
    }
    /* no fast operation found */
    return -1;
}
Ejemplo n.º 2
0
/* optimize float array or complex array to a scalar power */
static PyObject *
fast_scalar_power(PyArrayObject *a1, PyObject *o2, int inplace)
{
    double exponent;
    NPY_SCALARKIND kind;   /* NPY_NOSCALAR is not scalar */

    if (PyArray_Check(a1) && ((kind=is_scalar_with_conversion(o2, &exponent))>0)) {
        PyObject *fastop = NULL;
        if (PyArray_ISFLOAT(a1) || PyArray_ISCOMPLEX(a1)) {
            if (exponent == 1.0) {
                /* we have to do this one special, as the
                   "copy" method of array objects isn't set
                   up early enough to be added
                   by PyArray_SetNumericOps.
                */
                if (inplace) {
                    Py_INCREF(a1);
                    return (PyObject *)a1;
                } else {
                    return PyArray_Copy(a1);
                }
            }
            else if (exponent == -1.0) {
                fastop = n_ops.reciprocal;
            }
            else if (exponent ==  0.0) {
                fastop = n_ops._ones_like;
            }
            else if (exponent ==  0.5) {
                fastop = n_ops.sqrt;
            }
            else if (exponent ==  2.0) {
                fastop = n_ops.square;
            }
            else {
                return NULL;
            }

            if (inplace) {
                return PyArray_GenericInplaceUnaryFunction(a1, fastop);
            } else {
                return PyArray_GenericUnaryFunction(a1, fastop);
            }
        }
        /* Because this is called with all arrays, we need to
         *  change the output if the kind of the scalar is different
         *  than that of the input and inplace is not on ---
         *  (thus, the input should be up-cast)
         */
        else if (exponent == 2.0) {
            fastop = n_ops.multiply;
            if (inplace) {
                return PyArray_GenericInplaceBinaryFunction
                    (a1, (PyObject *)a1, fastop);
            }
            else {
                PyArray_Descr *dtype = NULL;
                PyObject *res;

                /* We only special-case the FLOAT_SCALAR and integer types */
                if (kind == NPY_FLOAT_SCALAR && PyArray_ISINTEGER(a1)) {
                    dtype = PyArray_DescrFromType(NPY_DOUBLE);
                    a1 = (PyArrayObject *)PyArray_CastToType(a1, dtype,
                            PyArray_ISFORTRAN(a1));
                    if (a1 == NULL) {
                        return NULL;
                    }
                }
                else {
                    Py_INCREF(a1);
                }
                res = PyArray_GenericBinaryFunction(a1, (PyObject *)a1, fastop);
                Py_DECREF(a1);
                return res;
            }
        }
    }
    return NULL;
}