What prints out from the println I suggested be added to the code? That will show where the lines are being drawn.
Also posted at: DrawLine loop - Dev Shed
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The printout would be easier if the numbers for each line were all on one line and if all the numbers had Strings for labels:
System.out.println("first="+first+", sec="+sec + ....
It looks like some of the numbers are out of range: 42500
These points won't be in the viewing area. Have you tried to plot the lines on a graph paper from the x,y values that were printed?