isNegativeInteger

Test if a finite double-precision floating-point number is a negative integer.

Usage

var isNegativeInteger = require( '@stdlib/math/base/assert/is-negative-integer' );

isNegativeInteger( x )

Tests if a finite double-precision floating-point number is a negative integer.

var bool = isNegativeInteger( -1.0 );
// returns true

bool = isNegativeInteger( 0.0 );
// returns false

bool = isNegativeInteger( 10.0 );
// returns false

Notes

The function assumes a finite number. If provided negative infinity, the function will return true, when, in fact, the result is undefined. If x can be infinite, wrap the implementation as follows:
```
function check( x ) {
    return (
        x > -Infinity &&
        isNegativeInteger( x )
    );
}

var bool = check( -Infinity );
// returns false
```

Examples

var isNegativeInteger = require( '@stdlib/math/base/assert/is-negative-integer' );

var bool = isNegativeInteger( -5.0 );
// returns true

bool = isNegativeInteger( 0.0 );
// returns false

bool = isNegativeInteger( 1.0 );
// returns false

bool = isNegativeInteger( -3.14 );
// returns false

bool = isNegativeInteger( NaN );
// returns false

C APIs

Usage

#include "stdlib/math/base/assert/is_negative_integer.h"

stdlib_base_is_negative_integer( x )

Tests if a finite double-precision floating-point number is a negative integer.

#include <stdbool.h>

bool out = stdlib_base_is_negative_integer( -4.0 );
// returns true

out = stdlib_base_is_negative_integer( 3.0 );
// returns false

The function accepts the following arguments:

x: [in] double input value.

bool stdlib_base_is_negative_integer( const double x );

Examples

#include "stdlib/math/base/assert/is_negative_integer.h"
#include <stdio.h>
#include <stdbool.h>

int main( void ) {
    const double x[] = { 5.0, -5.0, 3.14, -3.14, 0.0, 0.0/0.0 };

    bool b;
    int i;
    for ( i = 0; i < 6; i++ ) {
        b = stdlib_base_is_negative_integer( x[ i ] );
        printf( "Value: %lf. Is negative integer? %s.\n", x[ i ], ( b ) ? "True" : "False" );
    }
}