gnuplot documentation

70 SET-SHOW gnuplot 4.3 87
To draw an arrow with relative end point in logarithmic x axis, use:
set logscale x
set arrow from 100,-5 rto 10,10
This draws an arrow from 100,-5 to 1000,5. For the logarithmic x axis, the relative coordinate 10 means
"factor 10" while for the linear y axis, the relative coordinate 10 means "difference 10".
To delete arrow number 2, use:
unset arrow 2
To delete all arrows, use:
unset arrow
To show all arrows (in tag order), use:
show arrow
arrows demos.
70.3 Autoscale
Autoscaling may be set individually on the x, y or z axis or globally on all axes.
autoscale all axes.
Syntax:
set autoscale {{|min|max|fixmin|fixmax|fix} | fix | keepfix}
unset autoscale {}
show autoscale
The default is to
where is either x, y, z, cb, x2, y2 or xy. A keyword with min or max appended (this cannot
be done with xy) tells gnuplot to autoscale just the minimum or maximum of that axis. If no keyword
is given, all axes are autoscaled.
A keyword with fixmin, fixmax or fix appended tells gnuplot to disable extension of the axis range to
the next tic mark position, for autoscaled axes using equidistant tics; set autoscale fix sets this for all
axes. Command set autoscale keepfix autoscales all axes while keeping the fix settings.
When autoscaling, the axis range is automatically computed and the dependent axis (y for a plot and
z for splot) is scaled to include the range of the function or data being plotted.
If autoscaling of the dependent axis (y or z) is not set, the current y or z range is used.
Autoscaling the independent variables (x for plot and x,y for splot) is a request to set the domain to
match any data file being plotted. If there are no data files, autoscaling an independent variable has no
effect. In other words, in the absence of a data file, functions alone do not affect the x range (or the y
range if plotting z = f(x,y)).
Please see set xrange (p. 142) for additional information about ranges.
The behavior of autoscaling remains consistent in parametric mode, (see set parametric (p. 118)).
However, there are more dependent variables and hence more control over x, y, and z axis scales. In
parametric mode, the independent or dummy variable is t for plots and u,v for splots. autoscale
in parametric mode, then, controls all ranges (t, u, v, x, y, and z) and allows x, y, and z to be fully
autoscaled.
Autoscaling works the same way for polar mode as it does for parametric mode for plot, with the
extension that in polar mode set dummy can be used to change the independent variable from t (see
set dummy (p. 98)).
When tics are displayed on second axes but no plot has been specified for those axes, x2range and
y2range are inherited from xrange and yrange. This is done before xrange and yrange are autoextended
to a whole number of tics, which can cause unexpected results. You can use the fixmin or fixmax
options to avoid this.
Examples:
This sets autoscaling of the y axis (other axes are not affected):