Port of gnuplot-pipe egg for Chicken Scheme to Chez Scheme.
gnuplot-pipe requires Gnuplot (tested with version 5.2).
$ akku install gnuplot-pipe
For more information on getting started with Akku, see this blog post.
It is recommended to import gnuplot-pipe using a prefix, for example gp:.
(import (prefix (gnuplot-pipe) gp:))
All gnuplot-pipe procedures calls must be wrapped by
(gp:call/gnuplot
...)
The default Gnuplot executable name is gnuplot. A different executable name (signaled by a warning) may cause the interpreter to crash.
The procedure gp:send is a simple pipe to gnuplot. Pass arbitrary command as string.
(gp:call/gnuplot
(gp:send "set xlabel 'x'")
(gp:send "plot sin(x)"))
Plot list of numbers as x and y coordinates with gp:plot. A new Gnuplot window will open at each plot.
(gp:call/gnuplot
;;; Plot x and y axes data as lines.
(gp:plot "title 'x^2'" '(1 2 3 4) '(1 4 9 16)))
Save the last plot with gp:save.
(gp:call/gnuplot
;;; Plot multiple curves.
(gp:plot '(("title 'x^2'" (1 2 3 4) (1 4 9 16))
("title 'x^3'" (1 2 3 4) (1 8 27 64))))
;;; Save last plot.
(gp:save "plot.png"))
To avoid a persistent Gnuplot window after each plot (especially when running compiled code to save plots on file), set an interactive terminal (qt, wxt, x11, ...) as non-persistent. For example:
(gp:call/gnuplot
(gp:send "set terminal x11 nopersist")
...)
Plot 3D data with gp:plot3d.
(gp:call/gnuplot
(gp:send "unset key")
(gp:send "set style data points")
(gp:send "set title 'The valley of the Gnu'")
(gp:plot3d ""
'(0 0 0 1 1 1 2 2 2 3 3 3)
'(0 1 2 0 1 2 0 1 2 0 1 2)
'(10 10 10 10 5 10 10 1 10 10 0 10)))
Draw multiple data similarly as for 2D plots.
Think of each list of numbers passed to gp:plot and gp:plot3d as a column passed as inline data in a Gnuplot script. The string passed to a plot element corresponds to properties optionally passed to the plot commands. For instance, the following Gnuplot script draws a pie chart with inline data.
set xrange [-15:15]
set style fill transparent solid 0.9 noborder
plot '-' using 1:2:3:4:5:6 with circles lc var
0 0 5 0 30 1
0 0 5 30 70 2
0 0 5 70 120 3
0 0 5 120 230 4
0 0 5 230 360 5
e
It is easily translated as follows.
(gp:call/gnuplot
(gp:send "set xrange [-15:15]")
(gp:send "set style fill transparent solid 0.9 noborder")
(gp:plot "using 1:2:3:4:5:6 with circles lc var"
'(0 0 0 0 0) '(0 0 0 0 0) '(5 5 5 5 5)
'(0 30 70 120 230) '(30 70 120 230 360) '(1 2 3 4 5)))
For more involved plots, additional specifications may be required. Consider the following Gnuplot script with inline data where we need to specify the data end e twice:
plot ’-’ matrix with image
5 4 3 1 0
2 2 0 0 1
0 0 0 1 0
0 1 2 4 3
e
e
When drawing the same image with gp:plot we need to declare the second data end signal manually:
(gp:call/gnuplot
(gp:plot "matrix with image"
'(5 2 0 0) '(4 2 0 1) '(3 0 0 2) '(1 0 1 4) '(0 1 0 3))
(gp:end-data)) ; Send end signal a second time manually.
[syntax] (call/gnuplot expr1 expr2 ...)
Evaluate expressions redirecting output towards Gnuplot pipe. All procedures defined in this API must be used as gp:call/gnuplot expressions.
[procedure] (send cmdline)
Send arbitrary command to Gnuplot as string.
[procedure] (plot . element)
Draw 2D data. This is a wrapper for the Gnuplot plot command offering many different graphical representations for data. A plot element can be given in the form:
(plot str list1 list2 ...)
where str is a (possibly empty) string with optional properties corresponding to Gnuplot axes <axes>, <title-spec> and with <style> specifications (see the Gnuplot manual or launch gnuplot -e "help plot" for more information). List of numbers list1, list2, ... are passed to Gnuplot as inline data columns.
To draw multiple sets of data, a plot element can be also given in the form:
(plot '((str-1 list1-1 list2-1 ...)
(str-2 list1-2 list2-2 ...)
...))
[procedure] (plot3d . element)
Draw 2D projections of 3D data. This is a wrapper for the Gnuplot splot command. Plot elements must be in the same format as in the gp:plot procedure.
[procedure] (save fname)
Save last plot to file. Permitted file name fname extensions are: png, pdf, svg, txt.
[procedure] (end-data)
Send end data signal e to Gnuplot pipe and flush output.