Re: Adding some new transformations to gnuplot (arctan and power laws)

[Ethan M. <merritt@u.washington.edu>]

On Tuesday 02 June 2009, James R. Van Zandt wrote:

[snipped most of it]

> Ethan Merritt wrote:
> > >  + how to pass the transform to an external helper (gnuplot_x11) or wrap it
> > >    in the driver output (canvas terminal)?
> 
> Surely that interface, in both directions, can be in terminal coordinates?

The issue is clearest for the canvas terminal, where "both directions" does not
apply.  I want to toggle between linear/logscale or linear/transform in the
javascript code on the browser.  There is no back-connection to the original
gnuplot run.  

I am arguing that it may be preferable to send terminal coordinates corresponding
to linear scale, plus some clue how they should be transformed by the viewer
upon request.  

Right now the output from gnuplot is in terminal coordinates that represent either
linear or log scale depending upon what was set at the time the plot was created.
The routine gnuplot_mouse.js knows how to back-transform the stored terminal
coordinates to give back correct mousing if log-scale was in effect.
But it doesn't know how to toggle from linear to log display of the coordinates,
whatever scale they were originally on.  It wouldn't be very hard to add that,
just tedious. I was putting it off in the hope that we might come up with a general
plan for toggling transformed data, so that I could write the routines only once
instead of having to redo them later.