INIT Routine

The first entry in any subdivision calculation is the INIT routine. This will clear, (or initialize) , an area in the points file, large enough to hold all the co-ordinates of the points to be calculated. The INIT routine can also be used subsequently to erase any unwanted points.

This routine is particularly important as it tells the program how many points will be defined, the lowest point number is placed in the unknown point column, and the highest point number placed in the known point column.

The initialisation of the points actually causes the program to write a special value into each point. When a point is used later to define other points, it's value is checked to see that it is not the special value. If it is, the program assumes that the point has not been defined, and will print an error. The special value is 123456789.0 which is written into the Easting value of each point in the INIT range of points.

The program will print an error message if the range of points is illegal or outside the size of the points file.

       XY Data Point Record          Col 
           Record Type  02           1
                Routine INIT         2
            Start Point ____         3
              End Point ____         4