[RFC]: add JS implementation for `sign`

[Pranavchiku]

Description

This RFC proposes adding JS implementation equivalent to sign present in Fortran. This is used often in LAPACK/BLAS packages.

/**
* Returns `x` multipled by `signum( y )`.
*
* @param {number} x - scalar element
* @param {number} y - scalar element
* @returns {number} computed value
*
* @example
* var out = sign( 1.0, -0.9 );
* // out => -1.0
*/
function sign( x, y ) {
	return x * signum( y );
}

Where we already have implementation for signum

alias: @stdlib/math/base/special/sign
reference: @stdlib/math/base/special/max

Related Issues

Related issues #2464.

Questions

No.

Other

cc @kgryte

Checklist

• I have read and understood the Code of Conduct.
• Searched for existing issues and pull requests.
• The issue name begins with RFC:.

[kgryte]

@Pranavchiku How is this different from copysign?

[Pranavchiku]

I missed it, sorry, closing it.

Note: Use copysign in #2819.