time-to-botec/squiggle/node_modules/@stdlib/stats/base/dmax/src/dmax.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

62 lines
1.5 KiB
C

/**
* @license Apache-2.0
*
* Copyright (c) 2020 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/stats/base/dmax.h"
#include "stdlib/math/base/assert/is_nan.h"
#include "stdlib/math/base/assert/is_positive_zero.h"
#include <stdint.h>
/**
* Computes the maximum value of a double-precision floating-point strided array.
*
* @param N number of indexed elements
* @param X input array
* @param stride stride length
* @return output value
*/
double stdlib_strided_dmax( const int64_t N, const double *X, const int64_t stride ) {
double max;
int64_t ix;
int64_t i;
double v;
if ( N <= 0 ) {
return 0.0 / 0.0; // NaN
}
if ( N == 1 || stride == 0 ) {
return X[ 0 ];
}
if ( stride < 0 ) {
ix = (1-N) * stride;
} else {
ix = 0;
}
max = X[ ix ];
for ( i = 1; i < N; i++ ) {
ix += stride;
v = X[ ix ];
if ( stdlib_base_is_nan( v ) ) {
return v;
}
if ( v > max || ( v == max && stdlib_base_is_positive_zero( v ) ) ) {
max = v;
}
}
return max;
}