Pow() returns NaN on negative decimal powers

Monkey Forums/Monkey Bug Reports/Pow() returns NaN on negative decimal powers

Difference

(Posted 2013) [#1]

Tested on HTML5 Chrome,and GLFW both Mac Lion, Monkey Version 66

Pow() returns NaN on negative decimal powers , eg .1.0 is ok but rasing a negative value to 0.5 or 1.1 returns NaN

Strict

Function Main:Int()

	For Local i:Float = -2 To 2 Step 0.01
	
		Local r:Float = Pow(i,1.1)
	
		Print r
	
	next
	
	Return 0

End Function

Floyd

(Posted 2013) [#2]

Those numbers are undefined.

Some of these make sense mathematically, such as x^2 being the same as x*x. So Pow( -x, 2 ) is okay. But Pow( negative, 0.5 ) would be the square root of a negative number, so it fails.

Likewise Pow( x, 1.1 ) can't work if x is negative. It would be the same as x * ( tenth root of x ). That fails for the same reason as square root of x.

Difference

(Posted 2013) [#3]

Ok, thanks, not a bug then.

And it explains why I end up doing this to create a super-ellipsis:

x = Cos(a)
y = Sin(a)

cpx = (Pow(Abs(x) ,factor)) * Sgn(x))
cpy = (Pow(Abs(y) ,factor)) * Sgn(y))