8:52 p.m.
Hello
I would like to save a plot/graph as a .png file using the c/c++ api. In order to do this
do I need to use header files from the gui folder. In particular do I need to use
gpt_control.h, and session.h? If there are an examples on how to save plot/graph as a .png
file that would be great, if not an overview on how to go about doing it would be much
appreciated.
Thank you
Ryan
1:21 p.m.
Am 08.03.2021 um 21:52 schrieb riles(a)triton.net:
Hello
I would like to save a plot/graph as a .png file using the c/c++ api. In order to do
this do I need to use header files from the gui folder. In particular do I need to use
gpt_control.h, and session.h? If there are an examples on how to save plot/graph as a .png
file that would be great, if not an overview on how to go about doing it would be much
appreciated.
Hi, I don't have an example, but I don't think the gui directory is
needed. Plotting in gretl happens through gnuplot also in the command
line environment, including libgretl (C level). Have you checked out
lib/src/graphing.c & .h?
cheers
sven
1:41 p.m.
Yes, I have looked at graphing.c and .h and I can't seem to find anything that would
allow for saving a graph as a .png file. If you create a graphing using graphing.c you can
not even save it manually by clicking on the graph(like you can if you use the gui
directly and not use the api.). gpt_control in the gui folder seems to handle saving the
plot as a png.
Also, what is a gpointer? I can't seem to find that any were, is it from a different
library that gretl uses?
in gpt_contol. c -> void save_graph_to_file (gpointer data, const char *fname)
3:38 p.m.
Am 09.03.2021 um 14:41 schrieb riles(a)triton.net:
Yes, I have looked at graphing.c and .h and I can't seem to find
anything that would allow for saving a graph as a .png file. If you create a graphing
using graphing.c you can not even save it manually by clicking on the graph(like you can
if you use the gui directly and not use the api.). gpt_control in the gui folder seems to
handle saving the plot as a png.
Also, what is a gpointer? I can't seem to find that any were, is it from a different
library that gretl uses?
in gpt_contol. c -> void save_graph_to_file (gpointer data, const char *fname)
I believe gpointer comes from the GTK GUI toolkit.
What about gp_set_up_batch in lib/src/graphing.c? It would seem to
recognize the png target (terminal) through the call to
set_term_type_from_fname.
(Again, never tested this myself, so take it with some grains of salt.)
cheers
sven
3:49 p.m.
I am unable to use gp_set_up_batch because it is not available through graphing.h
cheers
ryan
4:57 p.m.
Am 09.03.2021 um 16:49 schrieb riles(a)triton.net:
I am unable to use gp_set_up_batch because it is not available
through graphing.h
Of course.
Maybe some stuff in the plugins folder can serve as templates. In
plugins/fractals.c there's do_hurst_plot, for example.
The information there about the chosen option (including the filename
and its png extension) seems to be in PLOT_HURST. (Although I'm not sure
at all if that latter statement is correct; in any case it is a PlotType
available through lib/src/graphing.h.)
Even if that assumption is correct, it's not clear to me, however, how
to manipulate PLOT_HURST at the libgretl level to inject the desired
filename, i.e. how exactly libgretl processes the options entered in the
client programs (gretlcli or the GUI client). Sorry. Only the libgretl C
wizard will be able to help, I guess!
cheers
sven
5:29 p.m.
To control the plot output type, you'll need set_optval_string() (in
options.h). You'd do something like this:
set_optval_string(GNUPLOT, OPT_U, "/path/to/plot.png");
OPT_U corresponds to the "--output=whatever" option for the "gnuplot"
command in gretl. If you're using a more specific plotting command
than plain GNUPLOT, substitute it in the call to set_optval_string.
Examples: FREQ, CORR.
Allin
On Tue, Mar 9, 2021 at 10:50 AM <riles(a)triton.net> wrote:
>
> I am unable to use gp_set_up_batch because it is not available through graphing.h
6:16 p.m.
Sven thank you for looking at the problem
Allin, thank you so much for the answer
I really appreciate the help, I spent many many hours trying to figure this out.
Thank you again
Ryan
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Cottrell, Allin -
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Sven Schreiber