Help with graph code example

Hi, I've been trying so long and i could not solve any of the problems (below) that I've been having for some time. If any of you could help out with any of the problems, that's be absolutely amazing.

- Graph Class Library

that's the website from which i got my plotting codes/classes for a plot that supposedly takes a set of data from a different calculating program (example 3 code is the one where you can load data). I'm looking at the graph code example3 and it's not obvious to me how to call up the data for the graph. is it where it says "DATA"? if the data file is called output.txt would i just substitute "output.txt" for "DATA"?

- How would i make it so that my outout.txt file from a calculating program is composed of two columns (so basically a set of data, x coordinates and y coordinates)?

- In the following equation, i want P to be varying b/t two given constants Pmax and Pmin. how would i do that?

public double I0(double Vb, double P, double Pbath) {

return ((Pbath-P)/Vb);

}

Thanks