dmaxabs

Compute the maximum absolute value of a one-dimensional double-precision floating-point ndarray.

Installation

npm install @stdlib/stats-base-ndarray-dmaxabs

Usage

var dmaxabs = require( '@stdlib/stats-base-ndarray-dmaxabs' );

dmaxabs( arrays )

Computes the maximum absolute value of a one-dimensional double-precision floating-point ndarray.

var Float64Array = require( '@stdlib/array-float64' );
var ndarray = require( '@stdlib/ndarray-base-ctor' );

var xbuf = new Float64Array( [ -1.0, 3.0, -4.0, 2.0 ] );
var x = new ndarray( 'float64', xbuf, [ 4 ], [ 1 ], 0, 'row-major' );

var v = dmaxabs( [ x ] );
// returns 4.0

The function has the following parameters:

• arrays: array-like object containing a one-dimensional input ndarray.

Notes

• If provided an empty one-dimensional ndarray, the function returns NaN.

Examples

var discreteUniform = require( '@stdlib/random-array-discrete-uniform' );
var ndarray = require( '@stdlib/ndarray-base-ctor' );
var ndarray2array = require( '@stdlib/ndarray-to-array' );
var dmaxabs = require( '@stdlib/stats-base-ndarray-dmaxabs' );

var xbuf = discreteUniform( 10, -50, 50, {
    'dtype': 'float64'
});
var x = new ndarray( 'float64', xbuf, [ xbuf.length ], [ 1 ], 0, 'row-major' );
console.log( ndarray2array( x ) );

var v = dmaxabs( [ x ] );
console.log( v );

C APIs

Usage

#include "stdlib/stats/base/ndarray/dmaxabs.h"

stdlib_stats_dmaxabs( arrays )

Computes the maximum absolute value of a one-dimensional double-precision floating-point ndarray.

#include "stdlib/ndarray/ctor.h"
#include "stdlib/ndarray/dtypes.h"
#include "stdlib/ndarray/index_modes.h"
#include "stdlib/ndarray/orders.h"
#include "stdlib/ndarray/base/bytes_per_element.h"
#include <stdint.h>

// Create an ndarray:
const double data[] = { 1.0, -2.0, 3.0, -4.0 };
int64_t shape[] = { 4 };
int64_t strides[] = { STDLIB_NDARRAY_FLOAT64_BYTES_PER_ELEMENT };
int8_t submodes[] = { STDLIB_NDARRAY_INDEX_ERROR };

struct ndarray *x = stdlib_ndarray_allocate( STDLIB_NDARRAY_FLOAT64, (uint8_t *)data, 1, shape, strides, 0, STDLIB_NDARRAY_ROW_MAJOR, STDLIB_NDARRAY_INDEX_ERROR, 1, submodes );

// Compute the maximum absolute value:
const struct ndarray *arrays[] = { x };
double v = stdlib_stats_dmaxabs( arrays );
// returns 4.0

// Free allocated memory:
stdlib_ndarray_free( x );

The function accepts the following arguments:

• arrays: [in] struct ndarray** list containing a one-dimensional input ndarray.

double stdlib_stats_dmaxabs( const struct ndarray *arrays[] );

Examples

#include "stdlib/stats/base/ndarray/dmaxabs.h"
#include "stdlib/ndarray/ctor.h"
#include "stdlib/ndarray/dtypes.h"
#include "stdlib/ndarray/index_modes.h"
#include "stdlib/ndarray/orders.h"
#include "stdlib/ndarray/base/bytes_per_element.h"
#include <stdint.h>
#include <stdlib.h>
#include <stdio.h>

int main( void ) {
    // Create a data buffer:
    const double data[] = { 1.0, -2.0, 3.0, -4.0, 5.0, -6.0, 7.0, -8.0 };

    // Specify the number of array dimensions:
    const int64_t ndims = 1;

    // Specify the array shape:
    int64_t shape[] = { 4 };

    // Specify the array strides:
    int64_t strides[] = { 2*STDLIB_NDARRAY_FLOAT64_BYTES_PER_ELEMENT };

    // Specify the byte offset:
    const int64_t offset = 0;

    // Specify the array order:
    const enum STDLIB_NDARRAY_ORDER order = STDLIB_NDARRAY_ROW_MAJOR;

    // Specify the index mode:
    const enum STDLIB_NDARRAY_INDEX_MODE imode = STDLIB_NDARRAY_INDEX_ERROR;

    // Specify the subscript index modes:
    int8_t submodes[] = { STDLIB_NDARRAY_INDEX_ERROR };
    const int64_t nsubmodes = 1;

    // Create an ndarray:
    struct ndarray *x = stdlib_ndarray_allocate( STDLIB_NDARRAY_FLOAT64, (uint8_t *)data, ndims, shape, strides, offset, order, imode, nsubmodes, submodes );
    if ( x == NULL ) {
        fprintf( stderr, "Error allocating memory.\n" );
        exit( 1 );
    }

    // Define a list of ndarrays:
    const struct ndarray *arrays[] = { x };

    // Compute the maximum absolute value:
    double v = stdlib_stats_dmaxabs( arrays );

    // Print the result:
    printf( "maxabs: %lf\n", v );

    // Free allocated memory:
    stdlib_ndarray_free( x );
}

Notice

This package is part of stdlib, a standard library for JavaScript and Node.js, with an emphasis on numerical and scientific computing. The library provides a collection of robust, high performance libraries for mathematics, statistics, streams, utilities, and more.

For more information on the project, filing bug reports and feature requests, and guidance on how to develop stdlib, see the main project repository.

Community

License

See LICENSE.

Copyright

Copyright © 2016-2026. The Stdlib Authors.