Display axis

Hello people

I create a 2 dimensional array
float [][] werte = new float[][] {{-3.0f, -0.5f, 0.0f, 1.5f, 3.0f} ,
{0.0f, 10.75f, 45.0f, 33.75f, 0.0f,} };
Now i want to display these points in my display (x,y).
My display draws the points but does not connect them to lines or
How can i connect these points without loosing the ability
to choose the exact coordinates on both axis ?????

Thanks to everyone