Hello,
I'm new at this, and I don't understand a lot, so if this has been discussed else where, please forgive me, I am very confused.

I am trying to pass data from one array into another? Is that the way you say it?

I am reading values from a text file, then trying to give that output to another array for display. Here is a code snippet, does anyone know what's going on and how I should be looking at this?

In the draw loop I have:

if (index < lines.length) {
   String[] pieces = split(lines[index], '\t');
   if (pieces.length == 2) {
     int x = int(pieces[0]) * 2;
     int y = int(pieces[1]) * 2;
     int da = x-y;
     println(da); //this is the info i want to pass down
    // return da;
     }
     // Go to the next line for the next run through draw()
     index = index + 1;
 }

In the setUp loop there is:
 for (int i=0; i < springs.length; i++){
   springs[i] = new Spring(nodeA, nodes[i]);
  springs[i] .setLength(100);
  springs[i] .setStiffness(da);
  springs[i] .setDamping(0.3);
  }

but even if I move this to the draw loop, it does not change anything.
Sorry if this is a bother, and thank you for your attention.

I'm not sure where exactly your code is placed, but variables defined within a function(including setup and draw) are not accessible outside that function.  It appears as if you have defined da within draw and are trying to access it in the separate function setup and before it is defined.  Try defining the variable at the top of the sketch before setup.  if that doesn't work try passing da to the springs array as the srtings are parsed:

Code:

if (index < lines.length) {
   String[] pieces = split(lines[index], '\t');
   if (pieces.length == 2) {
     int x = int(pieces[0]) * 2;
     int y = int(pieces[1]) * 2;
     int da = x-y;
     println(da); //this is the info i want to pass down
    
    springs[index] .setLength(100);
    springs[index] .setStiffness(da);
    springs[index] .setDamping(0.3);
    
     }
     // Go to the next line for the next run through draw()
     index = index + 1;
 }
 

hope that helped