Function PyArray_MultiIndexSetItem

numpy/core/src/multiarray/item_selection.c:3084–3105

* Sets a single item in the array, based on a single multi-index * array of values, which must be of length PyArray_NDIM(self). * * Returns 0 on success, -1 on failure. */

 * Returns 0 on success, -1 on failure.
 */
NPY_NO_EXPORT int
PyArray_MultiIndexSetItem(PyArrayObject *self, const npy_intp *multi_index,
                                                PyObject *obj)
{
    int idim, ndim = PyArray_NDIM(self);
    char *data = PyArray_DATA(self);
    npy_intp *shape = PyArray_SHAPE(self);
    npy_intp *strides = PyArray_STRIDES(self);

    /* Get the data pointer */
    for (idim = 0; idim < ndim; ++idim) {
        npy_intp shapevalue = shape[idim];
        npy_intp ind = multi_index[idim];

        if (check_and_adjust_index(&ind, shapevalue, idim, NULL) < 0) {
            return -1;
        }
        data += ind * strides[idim];
    }

    return PyArray_Pack(PyArray_DESCR(self), data, obj);
}