Next: Devices, Previous: Managing Curves, Up: Graphics

The `g g` (`calc-graph-grid`

) command turns the “grid”
on and off. It is off by default; tick marks appear only at the
edges of the graph. With the grid turned on, dotted lines appear
across the graph at each tick mark. Note that this command only
changes the setting in ‘`*Gnuplot Commands*`’; to see the effects
of the change you must give another `g p` command.

The `g b` (`calc-graph-border`

) command turns the border
(the box that surrounds the graph) on and off. It is on by default.
This command will only work with GNUPLOT 3.0 and later versions.

The `g k` (`calc-graph-key`

) command turns the “key”
on and off. The key is a chart in the corner of the graph that
shows the correspondence between curves and line styles. It is
off by default, and is only really useful if you have several
curves on the same graph.

The `g N` (`calc-graph-num-points`

) command allows you
to select the number of data points in the graph. This only affects
curves where neither “x” nor “y” is specified as a vector.
Enter a blank line to revert to the default value (initially 15).
With no prefix argument, this command affects only the current graph.
With a positive prefix argument this command changes or, if you enter
a blank line, displays the default number of points used for all
graphs created by `g a` that don't specify the resolution explicitly.
With a negative prefix argument, this command changes or displays
the default value (initially 5) used for 3D graphs created by `g A`.
Note that a 3D setting of 5 means that a total of ‘`5^2 = 25`’ points
will be computed for the surface.

Data values in the graph of a function are normally computed to a
precision of five digits, regardless of the current precision at the
time. This is usually more than adequate, but there are cases where
it will not be. For example, plotting ‘`1 + x`’ with ‘`x`’ in the
interval ‘`[0 .. 1e-6]`’ will round all the data points down
to 1.0! Putting the command ‘`set precision n`’ in the
‘

The `g h` (`calc-graph-header`

) command sets the title
for the graph. This will show up centered above the graph.
The default title is blank (no title).

The `g n` (`calc-graph-name`

) command sets the title of an
individual curve. Like the other curve-manipulating commands, it
affects the most recently added curve, i.e., the last curve on the
list in the ‘`*Gnuplot Commands*`’ buffer. To set the title of
the other curves you must first juggle them to the end of the list
with `g j`, or edit the ‘`*Gnuplot Commands*`’ buffer by hand.
Curve titles appear in the key; if the key is turned off they are
not used.

The `g t` (`calc-graph-title-x`

) and `g T`
(`calc-graph-title-y`

) commands set the titles on the “x”
and “y” axes, respectively. These titles appear next to the
tick marks on the left and bottom edges of the graph, respectively.
Calc does not have commands to control the tick marks themselves,
but you can edit them into the ‘`*Gnuplot Commands*`’ buffer if
you wish. See the GNUPLOT documentation for details.

The `g r` (`calc-graph-range-x`

) and `g R`
(`calc-graph-range-y`

) commands set the range of values on the
“x” and “y” axes, respectively. You are prompted to enter a
suitable range. This should be either a pair of numbers of the
form, ‘` min:max`’, or a blank line to revert to the
default behavior of setting the range based on the range of values
in the data, or ‘

The `g l` (`calc-graph-log-x`

) and `g L` (`calc-graph-log-y`

)
commands allow you to set either or both of the axes of the graph to
be logarithmic instead of linear.

For 3D plots, `g C-t`, `g C-r`, and `g C-l` (those are
letters with the Control key held down) are the corresponding commands
for the “z” axis.

The `g z` (`calc-graph-zero-x`

) and `g Z`
(`calc-graph-zero-y`

) commands control whether a dotted line is
drawn to indicate the “x” and/or “y” zero axes. (These are the same
dotted lines that would be drawn there anyway if you used `g g` to
turn the “grid” feature on.) Zero-axis lines are on by default, and
may be turned off only in GNUPLOT 3.0 and later versions. They are
not available for 3D plots.

The `g s` (`calc-graph-line-style`

) command turns the connecting
lines on or off for the most recently added curve, and optionally selects
the style of lines to be used for that curve. Plain `g s` simply
toggles the lines on and off. With a numeric prefix argument, `g s`
turns lines on and sets a particular line style. Line style numbers
start at one and their meanings vary depending on the output device.
GNUPLOT guarantees that there will be at least six different line styles
available for any device.

The `g S` (`calc-graph-point-style`

) command similarly turns
the symbols at the data points on or off, or sets the point style.
If you turn both lines and points off, the data points will show as
tiny dots. If the “y” values being plotted contain error forms and
the connecting lines are turned off, then this command will also turn
the error bars on or off.

Another way to specify curve styles is with the `LineStyles`

and
`PointStyles`

variables. These variables initially have no stored
values, but if you store a vector of integers in one of these variables,
the `g a` and `g f` commands will use those style numbers
instead of the defaults for new curves that are added to the graph.
An entry should be a positive integer for a specific style, or 0 to let
the style be chosen automatically, or *-1* to turn off lines or points
altogether. If there are more curves than elements in the vector, the
last few curves will continue to have the default styles. Of course,
you can later use `g s` and `g S` to change any of these styles.

For example, `'[2 -1 3] <RET> s t LineStyles` causes the first curve
to have lines in style number 2, the second curve to have no connecting
lines, and the third curve to have lines in style 3. Point styles will
still be assigned automatically, but you could store another vector in
`PointStyles`

to define them, too.