time-to-botec/squiggle/node_modules/@stdlib/ndarray/base/minmax-view-buffer-index/src/main.c
NunoSempere b6addc7f05 feat: add the node modules
Necessary in order to clearly see the squiggle hotwiring.
2022-12-03 12:44:49 +00:00

71 lines
1.8 KiB
C

/**
* @license Apache-2.0
*
* Copyright (c) 2018 The Stdlib Authors.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include "stdlib/ndarray/base/minmax_view_buffer_index.h"
#include <stdint.h>
/**
* Computes the minimum and maximum linear indices (in bytes) in an underlying data buffer accessible to an array view.
*
* @param ndims number of dimensions
* @param shape array shape (dimensions)
* @param strides array strides (in bytes)
* @param offset index offset
* @param out 2-element output array
* @return status code
*
* @example
* #include "stdlib/ndarray/base/minmax_view_buffer_index.h"
* #include <stdint.h>
*
* int64_t ndims = 2;
* int64_t shape[] = { 10, 10 };
* int64_t strides[] = { 10, 1 };
* int64_t offset = 0;
* int64_t out[ 2 ];
*
* stdlib_ndarray_minmax_view_buffer_index( ndims, shape, strides, offset, out );
*
* int64_t min = out[ 0 ];
* // returns 0
*
* int64_t max = out[ 1 ];
* // returns 99
*/
int8_t stdlib_ndarray_minmax_view_buffer_index( int64_t ndims, int64_t *shape, int64_t *strides, int64_t offset, int64_t *out ) {
int64_t min;
int64_t max;
int64_t s;
int64_t i;
min = offset;
max = offset;
for ( i = 0; i < ndims; i++ ) {
s = strides[ i ];
if ( s > 0 ) {
max += s * ( shape[i]-1 );
} else if ( s < 0 ) {
min += s * ( shape[i]-1 ); // decrements min
}
}
out[ 0 ] = min;
out[ 1 ] = max;
return 0;
}