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3.2.2 logxy
You may want to choose among log, semilog, or ordinary linear scale
axes. Use the logxy command:
 logxy, 1, 1 // loglog plot
logxy, 1, 0 // semilog plot, x logarithmic
logxy, 0, 1 // semilog plot, y logarithmic
logxy, 0, 0 // linear axis scales

You can also omit the x or y flag to leave the scaling of that axis
unchanged:
changes the y axis to a log scale, leaving the x axis scaling
unchanged.
The flags returned by the limits function include the current logxy
settings, if you need them in a program.
Zero or negative values in your data have no catastrophic effects with
log axis scaling; Yorick takes the absolute value of your data and
adds a very small offset before applying the logarithm function. As a
side effect, you lose any indication of the sign of your data in a log
plot. If you insist you need a way to get log axis scaling for
oscillating data, write a function to treat negative points specially.
For example, to draw positivey portions solid and negativey portions
dashed, you might use a function like this:
 func logplg(y, x)
{
s = sum(y>=0.); /* number of positivey points */
n = numberof(y);
if (s) plg, max(y,0.), x, type="solid";
if (s<n) plg, min(y,0.), x, type="dash";
}

You always have the option of plotting the logarithm of a function,
instead of using log axes:
plots the same curve as
The log axis scaling merely changes the position of the ticks and
their labels; the y axis ticks will look like a slide rule scale in
the first case, but like an ordinary ruler in the second.
