#191 freq command: gnuplot tweaks

[Artur Tarassow]

Hi all,

currently the freq command does not allow to tweak the title, labels etc. as already supported for other plotting commands.

Here an example which currently fails with the error "Parse error at unexpected token ' set title "foo"; '"

set verbose off
open denmark
freq LRM --plot=display { set title "foo"; }

I think it's useful to add this option for freq, too.

Best,
Artur

[Allin Cottrell]

Note that this applies to all commands which can produce plots, but where the plot is not the sole or primary output. So corr, corrgm, cusum, fcast, hurst, leverage, pergm, qlrtest, xcorrgm as well as freq.

[Sven Schreiber]

Also related is [#178]: The common theme is that there's a group of commands (enumerated by Allin above) which mainly print output and optionally produce a plot. I guess we need to decide how the plotting-part is treated for that group.

[Sven Schreiber]

OK, here's the idea for a solution or workaround. First of all, you redirect the plotting output from the 'freq' (or other target) command to a string:

set verbose off
open denmark
string s
freq LRM --silent --outbuf=s
print s

This is actually tested and working on gretl 2023c. Note that the outbuf option isn't documented for freq and friends, perhaps it should be.
Then you load these plotting directives into gretl's 'gnuplot' command via the --inbuf option, and there you could manipulate other stuff like the plot's title, like this:
gnuplot --inbuf=s --output=display {set title 'heyho';}
While this doesn't work in gretl 2023c, Allin was kind enough to activate the combination of inbuf with literal gnuplot strings very recently, so it should be in 2023d or 2024a. (Not tested yet.)

[Sven Schreiber]

The example above is now tested and works on a current (as of Dec 19th) snapshot.
However, I'm not closing this just yet because a similar thing failed with other commands such as 'corr', 'corrgm'. So even though this ticket is originally only about 'freq', it's not clear to me whether the solution is valid.

[Sven Schreiber]

What I wrote previously about problems with 'corr' is not true, I think I simply did not read the doc, namely that for a plot three variables are needed.
There is, however, an incompatibility between the --plot and --outbuf options which affect corrgm, pergm, qlrtest, xcorrgm; I've just written a message to the devel list about that.
But the actual question and problem of this ticket can be solved using the trick given above, and so I'm closing this.