Programming in Emacs Lisp
C.2 The print-Y-axis Function
The job of the print-Y-axis function is to print a label for
the vertical axis that looks like this:
The function should be passed the height of the graph, and then should
construct and insert the appropriate numbers and marks.
It is easy enough to see in the figure what the Y axis label should
look like; but to say in words, and then to write a function
definition to do the job is another matter. It is not quite true to
say that we want a number and a tic every five lines: there are only
three lines between the `1' and the `5' (lines 2, 3, and 4),
but four lines between the `5' and the `10' (lines 6, 7, 8,
and 9). It is better to say that we want a number and a tic mark on
the base line (number 1) and then that we want a number and a tic on
the fifth line from the bottom and on every line that is a multiple of
five.
