Re: [Plplot-general] Log scale for frequency plot:

[Alan W. I. <Ala...@gm...>]

On 2020-05-05 21:45+0200 Raphael Raccuia wrote:

> Hi list,
> Any chance to get a custom x axis log scale?

Hi Raphael:

Thanks for your interest in PLplot, and the answer to your question is
"yes".

The best way to figure out how to do anything with PLplot
is to consult the code for one of our standard examples.

For example:

# Search for case-insensitive "custom" in our C example source code.
software@merlin> grep -i custom examples/c/*.c
examples/c/x02c.c:// Use 100 custom colors in addition to base 16
examples/c/x02c.c:// Load default cmap0 colors into our custom set
examples/c/x19c.c:// A custom axis labeling function for longitudes and latitudes.
examples/c/x19c.c:    // Setup a custom latitude and longitude-based scaling function.
examples/c/x19c.c:    plscol0( 8, 100, 100, 100 ); //dark grey for custom polygons - generally crags
examples/c/x33c.c:    "Shade colorbars with custom labels",

So example 19 looks promising for your needs.  Here is software for that example for our various languages:

software@merlin> ls -l examples/*/*19*
-rw-r--r-- 1 software software 15621 Jan 27 22:26 examples/ada/xstandard19a.adb
-rw-r--r-- 1 software software 14616 Jan 27 22:26 examples/ada/xtraditional19a.adb
-rw-r--r-- 1 software software 12104 Jan 27 22:26 examples/c++/x19.cc
-rw-r--r-- 1 software software  9911 Jan 27 22:26 examples/c/x19c.c
-rw-r--r-- 1 software software  9420 Jan 27 22:26 examples/d/x19d.d
-rw-r--r-- 1 software software 16424 Jan 27 22:26 examples/fortran/x19f.f90
-rw-r--r-- 1 software software 12440 Jan 27 22:26 examples/java/x19.java
-rw-r--r-- 1 software software  8549 Jan 27 22:26 examples/lua/x19.lua
-rw-r--r-- 1 software software  9405 Jan 27 22:26 examples/ocaml/x19.ml
-rw-r--r-- 1 software software  2154 Jan 27 22:26 examples/octave/p19.m
-rw-r--r-- 1 software software  8532 Jan 27 22:26 examples/octave/x19c.m
-rwxr-xr-x 1 software software  1158 Jan 27 22:26 examples/python/x19*
-rw-r--r-- 1 software software  9732 Jan 27 22:26 examples/python/x19.py
-rwxr-xr-x 1 software software   462 Jan 27 22:26 examples/tcl/x19.in*
-rw-r--r-- 1 software software  9425 Jan 27 22:26 examples/tcl/x19.tcl

Pick the language of interest to you, and go from there.  Or if you prefer
a GUI then consult <http://plplot.org/examples.php?demo=19>.

Alan
__________________________
Alan W. Irwin

Research affiliation with the Department of Physics and Astronomy,
University of Victoria, Victoria, BC, Canada.

Programming affiliations with the FreeEOS equation-of-state
implementation for stellar interiors (freeeos.sf.net); the Time
Ephemerides project (timeephem.sf.net); PLplot scientific plotting
software package (plplot.org); the libLASi project
(unifont.org/lasi); the Loads of Linux Links project (loll.sf.net);
and the Linux Brochure Project (lbproject.sf.net).
__________________________

Linux-powered Science
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