How to interpret situations where Math.Acos() reports invalid input?
- by Sean Ochoa
Hey all. I'm computing the angle between two vectors, and sometimes Math.Acos() returns NaN when it's input is out of bounds (-1 input && input 1) for a cosine. What does that mean, exactly? Would someone be able to explain what's happening? Any help is appreciated!
Here's me method:
public double AngleBetween(vector b)
{
var dotProd = this.Dot(b);
var lenProd = this.Len*b.Len;
var divOperation = dotProd/lenProd;
// http://msdn.microsoft.com/en-us/library/system.math.acos.aspx
return Math.Acos(divOperation) * (180.0 / Math.PI);
}
