I'm trying to make a line graph using data imported from a txt file. I want each line to go from one point to the next, but all I'm getting is a bunch of lines coming out of the last point on the right going to every other point. Here's the code that does that:

Code:

if (abs(mouseX-(NII*650+800)) < lim && 
  abs(mouseY-(-OIII*350+350)) < lim) {
 String spectra = "S5_hi_spectra_" + nf(i,5) + ".txt";
 println(spectra);
 String[] spec = loadStrings (spectra);
 for (int j = 1; j < 866; j++) {
 String[] spec1 = splitTokens(spec[j], WHITESPACE);
    float[] spec2 = parseFloat(spec1);
 for (int k = 2; k < 866; k++) {
 String[] spec3 = splitTokens(spec[k], WHITESPACE); 
     spec4 = parseFloat(spec3);
 }
    pushMatrix();
    pushStyle();
    fill(0);
    stroke(0);
    translate(50,900);
    scale(0.35);
    line(spec2[1]*100-1000, -spec2[2]*10000, spec4[1]*100-1000, -spec4[2]*10000); 

It worked fine when I used ellipses for points, instead of trying to make a line, but I need the points to be connected.

I tried what you suggested, and now it doesn't plot anything at all. Updated code:

Code:

if (abs(mouseX-(NII*650+800)) < lim && //transform
  abs(mouseY-(-OIII*350+350)) < lim) {
 String spectra = "S5_hi_spectra_" + nf(i,5) + ".txt";
 println(spectra);
 String[] spec = loadStrings (spectra);
 for (int j = 1; j < 866; j++) {
 String[] spec1 = splitTokens(spec[j], WHITESPACE);
    float[] spec2 = parseFloat(spec1);
    pushMatrix();
    pushStyle();
    fill(0);
    stroke(0);
    translate(50,900);
    scale(0.35);
    beginShape(LINES);
    vertex(spec2[1]*100-1000, -spec2[2]*10000);
    endShape();
 

The points are (spec2[1]*100-1000, -spec2[2]*10000), there's a whole list of almost 900 numbers in each one of those.

All the points are drawn every frame. This graph is actually within a bigger graph - when you roll over a point on the bigger graph, you get this smaller one. That's where the i in the nf(i,5) comes from.
I just use the "*100-1000" to make the points fit where I want them to.  I could probably find a better way to put that in the code, but this worked fine with the ellipses, so I don't think that's the problem. Here's the entire code for the graph that actually works, with the part we're working on highlighted:

Code:

int numPics = 292; // change with number of points, numPics = # pictures
PImage[] pics = new PImage[numPics];
PFont font;
PFont small;
PFont large;
String[] num;
float[] values;

void setup() {
  size(1000,950);
  smooth();
  font = loadFont("Serif-15.vlw"); 
  small = loadFont("Serif-12.vlw");
  large = loadFont("LiSongPro-32.vlw");
  for ( int k = 0; k < numPics; k++) {
    String imageName =  "S5_stamp_" + nf(k, 5) + ".png";
    pics[k] = loadImage(imageName);     
  }
}

void draw() {
  background(255);
  String[] data = loadStrings ("S5_quantities_4.txt"); 
 for (int i = 0; i < numPics; i++) {            
    num = splitTokens(data[i], WHITESPACE); 
    values = parseFloat(num);  
  ellipseMode(CENTER);
  stroke(150);
  fill(255);
  float NII = log(values[5]/values[4])/log(10);
  float OIII = log(values[7]/values[6])/log(10);
if(values[8] == 1) {
      fill(0,0,255);
      stroke(0,0,255);
    ellipse(NII*650+800,-OIII*350+350,3,3); //transform, disk
  }
else if(values[8] == 2) {
    fill(0,255,0);
    stroke(0,255,0);
  ellipse(NII*650+800,-OIII*350+350,3,3); //transform, peculiar
  }
  else {
    fill(255,0,0);
    stroke(255,0,0);
  ellipse(NII*650+800,-OIII*350+350,3,3); //transform, spheroid
}
  int lim = 2;
  if(abs(mouseX-(NII*650+800)) < lim && //transform
  abs(mouseY-(-OIII*350+350)) < lim) {
    image(pics[i-1], 50, 500, 120, 120); 
    textFont(font);
    fill(0);
    text("NII/Ha" + " " + NII + "  " + "OIII/Hb" + " " + OIII, 50, 630, 300, 60);
  }
    
 if (abs(mouseX-(NII*650+800)) < lim && //transform
  abs(mouseY-(-OIII*350+350)) < lim) {
 String spectra = "S5_hi_spectra_" + nf(i,5) + ".txt";
 println(spectra);
 String[] spec = loadStrings (spectra);
 for (int j = 0; j < 866; j++) {
 String[] spec1 = splitTokens(spec[j], WHITESPACE);
    float[] spec2 = parseFloat(spec1);
    pushMatrix();
    pushStyle();
    fill(0);
    stroke(0);
    translate(50,900);
    scale(0.35);
    ellipse(spec2[1]*100-1000, -spec2[2]*10000,1,1);
    line(-11,0,951,0);
    line(0,-550,0,10);
    for (int k = 0; k < width; k+=100) {
      line(k,0,k,20);
    }
   for (int k = 0; k < 600; k+=100) {
      line(0,-k,-20,-k);
    }
    popStyle();
    popMatrix();
 }
    textFont(small);
     float[] yscale = {0.05, 0.04, 0.03, 0.02, 0.01, 0.0};
    for (int k = 0; k < 6; k++) {
      text(nf(yscale[k],1,2), 15, k*35+725);
    }
    float[] xscale = {10, 11, 12, 13, 14, 15, 16, 17, 18, 19};
    for (int k = 0; k < 10; k++) {
      text(nf(xscale[k],0,0), k*35+45, 920);
    }
    text("Flux v. Wavelength", 175, 700);
 }
 } 
 
// axes and scales
stroke(0);
line(0,2,width,2); //horizontal
line(width-2,-height,width-2,height);    //vertical
textFont(font);
fill(0);
text("Log[NII]6584/Ha", 10, 35);
text("Log[OIII]5007/Hb", width-150, height-10);
fill(0,0,255);
text("disk", 10, 645);
fill(0,255,0);
text("peculiar", 10, 660);
fill(255,0,0);
text("spheroid", 10, 675);
fill(0);
for(int i = 0; i < height; i+=86) {
  line(width-4,i,width,i);
}
float[] yscale = {
  1.25, 1, 0.75, 0.5, 0.25, 0, -0.25, -0.5, -0.75, -1.0, -1.25, -1.5, -1.75};
for (int i = 0; i < 12; i++) {
  text(nf(yscale[i],0,2), width-40, (i-1)*86);
}

for(int i = -13; i < width; i+=167) {
  line(i,0,i,4);
}

float[] xscale = {
  -1.25, -1, -0.75, -0.5, -0.25, 0, 0.25, 0.5, 0.75, 1.0};
for(int i = 1; i < 6; i++) {
  text(nf(xscale[i],0,2), (i)*167-13, 15);
}
} 

This draws an entire graph of ellipses, spec2[1]*100-1000 vs -spec2[2]*10000.