gnuplot documentation

142 gnuplot 4.3 70 SET-SHOW
70.87 Xmtics
The set xmtics command converts the x-axis tic marks to months of the year where 1=Jan and 12=Dec.
Overflows are converted modulo 12 to months. The tics are returned to their default labels by unset
xmtics. Similar commands perform the same duties for the other axes.
Syntax:
set xmtics
unset xmtics
show xmtics
The same syntax applies to x2mtics, ymtics, y2mtics, zmtics and cbmtics.
See also the set format (p. 100) command.
70.88 Xrange
The set xrange command sets the horizontal range that will be displayed. A similar command exists
for each of the other axes, as well as for the polar radius r and the parametric variables t, u, and v.
Syntax:
set xrange { [{{}:{}}] {{no}reverse} {{no}writeback} }
| restore
show xrange
where and terms are constants, expressions or an asterisk to set autoscaling. If the data
are time/date, you must give the range as a quoted string according to the set timefmt format. Any
value omitted will not be changed.
The same syntax applies to yrange, zrange, x2range, y2range, cbrange, rrange, trange, urange
and vrange.
The reverse option reverses the direction of the axis, e.g., set xrange [0:1] reverse will produce an
axis with 1 on the left and 0 on the right. This is identical to the axis produced by set xrange [1:0],
of course. reverse is intended primarily for use with autoscale.
The writeback option essentially saves the range found by autoscale in the buffers that would be
filled by set xrange. This is useful if you wish to plot several functions together but have the range
determined by only some of them. The writeback operation is performed during the plot execution, so
it must be specified before that command. To restore, the last saved horizontal range use set xrange
restore. For example,
set xrange [-10:10]
set yrange [] writeback
plot sin(x)
set yrange restore
replot x/2
results in a yrange of [-1:1] as found only from the range of sin(x); the [-5:5] range of x/2 is ignored.
Executing show yrange after each command in the above example should help you understand what
is going on.
In 2-d, xrange and yrange determine the extent of the axes, trange determines the range of the
parametric variable in parametric mode or the range of the angle in polar mode. Similarly in parametric
3-d, xrange, yrange, and zrange govern the axes and urange and vrange govern the parametric
variables.
In polar mode, rrange determines the radial range plotted. acts as an additive constant to the
radius, whereas acts as a clip to the radius — no point with radius greater than will
be plotted. xrange and yrange are affected — the ranges can be set as if the graph was of r(t)-rmin,
with rmin added to all the labels.
Any range may be partially or totally autoscaled, although it may not make sense to autoscale a parametric
variable unless it is plotted with data.