Here the loadNumbers function asks for a file name, suppose the file contains 4 numbers in a row, two integers then two floats, all separated by tabs. It splits each line into four elements and convert them into numbers to assign to temporary variables x, y, fx, and fy. It also stores x values in an array. The array starts with zero elements and expands every time a new number is added.

void loadNumbers(String fileName)
{
 String[] lines;
 int[] xArray=new int[0];
 int index = 0;
 lines = loadStrings(fileName); //Ask file name.
 while (index < lines.length)
 {
   String[] pieces = split(lines[index], '\t');
   if (pieces.length == 4)
   {
     int x = int(pieces[0]);
     int y = int(pieces[1]);
     float fxm = float(pieces[2]);
     float fy = float(pieces[3]);
     xArray=(int[])append(xArray,x); // Add the new number to the end of the array.
   }
     index ++;
 }
 
 return (loadVectors);
}