private void GrathMath(string[] x, string[] y)
{
for (int i = 0; i<x.Length; i++)
{
x[i] = double.Parse(x[i]);
}
}
double [] doubleArray = new double[stringArray.Length]
for(int i=0; i<stringArray.Length; i++)
{
doubleArray[i] = Double.Parse(stringArray[i]);
}
double[] doubleArray = stringArray.Select<string, double>(s => Double.Parse(s)).ToArray<double>();