Compute the nth negaFibonacci number.
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Compute the nth [negaFibonacci number][fibonacci-number].
math
0, 1, -1, 2, -3, 5, -8, 13, -21, 34, -55, 89, -144, \ldotsmath
F_{n-2} = F_{n} - F_{n-1}math
F_{-n} = (-1)^{n+1} F_nF_0 = 0 and F_{-1} = 1.bash
npm install @stdlib/math-base-special-negafibonacciscript tag without installation and bundlers, use the [ES Module][es-module] available on the [esm][esm-url] branch (see [README][esm-readme]).deno][deno-url] branch (see [README][deno-readme] for usage intructions).umd][umd-url] branch (see [README][umd-readme]).javascript
var negafibonacci = require( '@stdlib/math-base-special-negafibonacci' );javascript
var v = negafibonacci( 0 );
// returns 0
v = negafibonacci( -1 );
// returns 1
v = negafibonacci( -2 );
// returns -1
v = negafibonacci( -3 );
// returns 2
v = negafibonacci( -78 );
// returns -8944394323791464n < -78, the function returns NaN, as larger [negaFibonacci numbers][fibonacci-number] cannot be safely represented in [double-precision floating-point format][ieee754].javascript
var v = negafibonacci( -79 );
// returns NaNNaN.javascript
var v = negafibonacci( -3.14 );
// returns NaN
v = negafibonacci( 1 );
// returns NaNNaN, the function returns NaN.javascript
var v = negafibonacci( NaN );
// returns NaNjavascript
var negafibonacci = require( '@stdlib/math-base-special-negafibonacci' );
var v;
var i;
for ( i = 0; i > -79; i-- ) {
v = negafibonacci( i );
console.log( v );
}c
#include "stdlib/math/base/special/negafibonacci.h"c
double out = stdlib_base_negafibonacci( 0 );
// returns 0
out = stdlib_base_negafibonacci( -1 );
// returns 1[in] int32_t input value.c
double stdlib_base_negafibonacci( const int32_t n );c
#include "stdlib/math/base/special/negafibonacci.h"
#include <stdio.h>
#include <stdint.h>
int main( void ) {
int32_t i;
double v;
for ( i = 0; i > -79; i-- ) {
v = stdlib_base_negafibonacci( i );
printf( "negafibonacci(%d) = %lf\n", i, v );
}
}
