feat: add math/base/special/negafibonaccif

PR-URL: #4939
Ref: #649

Signed-off-by: Gururaj Gurram <[email protected]>
Co-authored-by: stdlib-bot <[email protected]>
Co-authored-by: Karan Anand <[email protected]>
Reviewed-by: Shabareesh Shetty <[email protected]>
Reviewed-by: Karan Anand <[email protected]>

Author: 3 people

lib/node_modules/@stdlib/math/base/special/negafibonaccif/README.md

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+<!--
+
+@license Apache-2.0
+
+Copyright (c) 2025 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.
+
+-->
+
+# negaFibonaccif
+
+> Compute the nth [negaFibonacci number][fibonacci-number] as a [single-precision floating-point number][ieee754].
+
+<section class="intro">
+
+The [negaFibonacci numbers][fibonacci-number] are the integer sequence
+
+<!-- <equation class="equation" label="eq:negafibonacci_sequence" align="center" raw="0, 1, -1, 2, -3, 5, -8, 13, -21, 34, -55, 89, -144, \ldots" alt="NegaFibonacci sequence"> -->
+
+```math
+0, 1, -1, 2, -3, 5, -8, 13, -21, 34, -55, 89, -144, \ldots
+```
+
+<!-- </equation> -->
+
+The sequence is defined by the recurrence relation
+
+<!-- <equation class="equation" label="eq:negafibonacci_recurrence_relation" align="center" raw="F_{n-2} = F_{n} - F_{n-1}" alt="NegaFibonacci sequence recurrence relation"> -->
+
+```math
+F_{n-2} = F_{n} - F_{n-1}
+```
+
+<!-- </equation> -->
+
+which yields
+
+<!-- <equation class="equation" label="eq:negafibonacci_fibonacci" align="center" raw="F_{-n} = (-1)^{n+1} F_n" alt="NegaFibonacci relationship to Fibonacci numbers"> -->
+
+```math
+F_{-n} = (-1)^{n+1} F_n
+```
+
+<!-- </equation> -->
+
+with seed values `F_0 = 0` and `F_{-1} = 1`.
+
+</section>
+
+<!-- /.intro -->
+
+<section class="usage">
+
+## Usage
+
+```javascript
+var negafibonaccif = require( '@stdlib/math/base/special/negafibonaccif' );
+```
+
+#### negafibonaccif( n )
+
+Computes the nth [negaFibonacci number][fibonacci-number] as a [single-precision floating-point number][ieee754].
+
+```javascript
+var v = negafibonaccif( 0 );
+// returns 0
+
+v = negafibonaccif( -1 );
+// returns 1
+
+v = negafibonaccif( -2 );
+// returns -1
+
+v = negafibonaccif( -3 );
+// returns 2
+
+v = negafibonaccif( -36 );
+// returns -14930352
+```
+
+If `n < -36`, the function returns `NaN`, as larger [negaFibonacci numbers][fibonacci-number] cannot be safely represented in [single-precision floating-point format][ieee754].
+
+```javascript
+var v = negafibonaccif( -37 );
+// returns NaN
+```
+
+If not provided a nonpositive integer value, the function returns `NaN`.
+
+```javascript
+var v = negafibonaccif( -3.14 );
+// returns NaN
+
+v = negafibonaccif( 1 );
+// returns NaN
+```
+
+If provided `NaN`, the function returns `NaN`.
+
+```javascript
+var v = negafibonaccif( NaN );
+// returns NaN
+```
+
+</section>
+
+<!-- /.usage -->
+
+<section class="notes">
+
+</section>
+
+<!-- /.notes -->
+
+<section class="examples">
+
+## Examples
+
+<!-- eslint no-undef: "error" -->
+
+```javascript
+var logEachMap = require( '@stdlib/console/log-each-map' );
+var linspace = require( '@stdlib/array/base/linspace' );
+var negafibonaccif = require( '@stdlib/math/base/special/negafibonaccif' );
+
+var v = linspace( -36, 0, 37 );
+
+logEachMap( 'negafibonaccif(%d) = %0.4f', v, negafibonaccif );
+```
+
+</section>
+
+<!-- /.examples -->
+
+<!-- C interface documentation. -->
+
+* * *
+
+<section class="c">
+
+## C APIs
+
+<!-- Section to include introductory text. Make sure to keep an empty line after the intro `section` element and another before the `/section` close. -->
+
+<section class="intro">
+
+</section>
+
+<!-- /.intro -->
+
+<!-- C usage documentation. -->
+
+<section class="usage">
+
+### Usage
+
+```c
+#include "stdlib/math/base/special/negafibonaccif.h"
+```
+
+#### stdlib_base_negafibonaccif( n )
+
+Computes the nth [negaFibonacci number][fibonacci-number] as a [single-precision floating-point number][ieee754].
+
+```c
+float out = stdlib_base_negafibonaccif( 0 );
+// returns 0.0f
+
+out = stdlib_base_negafibonaccif( -1 );
+// returns 1.0f
+```
+
+The function accepts the following arguments:
+
+-   **n**: `[in] int32_t` input value.
+
+```c
+float stdlib_base_negafibonaccif( const int32_t n );
+```
+
+</section>
+
+<!-- /.usage -->
+
+<!-- C API usage notes. Make sure to keep an empty line after the `section` element and another before the `/section` close. -->
+
+<section class="notes">
+
+</section>
+
+<!-- /.notes -->
+
+<!-- C API usage examples. -->
+
+<section class="examples">
+
+### Examples
+
+```c
+#include "stdlib/math/base/special/negafibonaccif.h"
+#include <stdio.h>
+#include <stdint.h>
+
+int main( void ) {
+    int32_t i;
+    float v;
+
+    for ( i = 0; i > -37; i-- ) {
+        v = stdlib_base_negafibonaccif( i );
+        printf( "negafibonaccif(%d) = %f\n", i, v );
+    }
+}
+```
+
+</section>
+
+<!-- /.examples -->
+
+</section>
+
+<!-- /.c -->
+
+<!-- Section for related `stdlib` packages. Do not manually edit this section, as it is automatically populated. -->
+
+<section class="related">
+
+</section>
+
+<!-- /.related -->
+
+<!-- Section for all links. Make sure to keep an empty line after the `section` element and another before the `/section` close. -->
+
+<section class="links">
+
+[fibonacci-number]: https://en.wikipedia.org/wiki/Fibonacci_number
+
+[ieee754]: https://en.wikipedia.org/wiki/IEEE_754-1985
+
+<!-- <related-links> -->
+
+<!-- </related-links> -->
+
+</section>
+
+<!-- /.links -->