2.34  PLOT command

2.34.1  Syntax

plot mode points ... ...
plot mode + points ... ...
plot mode - points ... ...
plot mode CLEAR

2.34.2  Purpose

Select points in the circuit for graphic output. Select graphic output.

2.34.3  Status

The plotting leaves something to be desired. Only two signals can be plotted at a time. The output file is corrupt when plotting is on.


The `plot' command selects where to look at the circuit, or where to hook the oscilloscope probe.

There are separate lists of probe points for each type of analysis.

To list the probe points, use the bare command `plot'.

Syntax for each point is parameter(node)(limits), parameter(componentlabel)(limits), or parameter(index)(limits). Some require a dummy index.

For more information on the data available see the print command.

You must set the scaling. If you do not, the default range is fixed at -5 to 5. Gnucap cannot auto-scale because it generates the plot during simulation, so the necessary information is not available yet. Spice can auto-scale only because it waits for the simulation to complete before producing any output.

Plot uses the same variables as print. See the print command for a list of what is available.

The options plot and noplot on any analysis command turn plotting on and off a single run. The plot command turns plotting on and tabular output off. The print command turns plotting off and tabular output on.

You can add to or delete from an existing list by prefixing with + or -. plot ac + v(3) adds v(3) to the existing set of AC probes. plot ac - q(c5) removes q(c5) from the list. You can use the wildcard characters * and ? when deleting.

Plotting is limited to 2 items.

2.34.5  Examples

plot ac vm(12)(0,5) vm(13)(-5,5)
The magnitude of the voltage at node 12 with a range of 0 to 5, and node 13 with a range of -5 to 5 for AC analysis.

plot dc v(r26)
The voltage across R26 for DC analysis. Since there is no range, default values will be used.

plot tran v(r83)(0,5) p(r83)(0,1u)
Plot the voltage and power of R83 in the next transient analysis. The voltage scale is 0 to 5. The power scale is 0 to 1 microwatt.

List all the probes for all modes.

plot dc
Display the DC plot list.

plot ac CLear
Clear the AC list.