Vector Issues

//before conversion to sfml's vector class and should work anywhere
public static double[] AngleToVector(double degreesangle)
{
    double[] newvector = new double[2];
    newvector[0] = calcXOnlyVector(degreesangle % 360);
    newvector[1] = calcYOnlyVector(degreesangle % 360);
    return newvector;
}

public static double calcXOnlyVector(double angle)
{
    return Math.Cos(ToRadians(angle));
}
public static double calcYOnlyVector(double angle)
{
    return Math.Sin(ToRadians(angle));
}

//this line of code in the sprite class that is after the conversion to SFML Vector
VectorDirection += (MissingMathFunctions.AngleToVectorSFML(angledirection % 360) * this.Acceleration);