1.7.1 Line Indexes

The thickness and color of a line segment drawn by GRPH1 is specified with a 3-digit integer (nnm) called the line index. Even when outputting to a device that can only change either the thickness or color, two lines with different line indexes can be distinguished because the line indexes follow the rules below for thickness and color.

In a system where both the thickness and color can be changed, the first 2 digits (nn=0- 99) indicate the color index, and the last digit (m=0- 9) represents thickness. The standard color indexes from 1 to 5 indicate

1: white or black (foreground)
2: red
3: green
4: blue
5: yellow

Colors specified by larger indexes are defined in the color map file. The line thickness is specified by 1(fine) - 9(thick). With an output device in which only the line thickness can be changed, nn is read as m only when m=0. With an output device in which only the color can be changed, m is read as nn only when nn=0. Therefore, except in cases where the line thickness and color needs to be specified, specification with a single-digit index will make the lines distinguishable in a device-dependent method.