Magnitude of Complex(inf,inf) == inf

src/Numerics/Complex32.cs

@@ -188,6 +188,8 @@ namespace MathNet.Numerics
             {
                 float a = Math.Abs(_real);
                 float b = Math.Abs(_imag);
+                if (float.IsPositiveInfinity(a) && float.IsPositiveInfinity(b))
+                    return float.PositiveInfinity;
                 if (a > b)
                 {
                     double tmp = b / a;