lines of the plotting aml OR how do I change the x and y values to plot things on my map?
A. The calc aml command initiates a mathematical calculation. The line &s y [calc [extract 2 [show convert map %ul% page]] + 6 / 25.4] means extract the value of the second token or entry in the variable %ul%, convert it from map units to page unit (which is set to inches with the pageunits command in the plotting aml), and calculate or add 6 รท 25.4 to this value. Instead of figuring out what 6mm is in inches, we let the aml do the math by knowing that there are 25.4 mm in one inch. If we wanted to add a distance of 8 points to the extracted value we could replace 6 / 25.4 by 8 / 72 since we know that there are 72 points in one inch. We can have more then one mathematical expression to calculate as in 6 / 25.4 + 0.25 which would add 6mm plus one quarter of one inch to the extracted value.
