Re: Persistent confusion about gnuplot -persist

[Tatsuro M. <tma...@ya...>]

----- Original Message -----
> From: Ethan A Merritt
> To: gnuplot-beta
> Cc: 
> Date: 2014/9/23, Tue 03:43
> Subject: Persistent confusion about gnuplot -persist
> 
> 
> There have recently been several queries, bug reports, support requests,
> and so on that involve misunderstanding about what to expect from 
> gnuplot -persist    or    set term <foo> persist.
> 
> People seem to assume that if the window is still showing on the screen,
> they should be able to pan/zoom/unzoom and so on using the mouse
> buttons or the widgets at the top of the terminal GUI.  
> 
> The documentation is quite explicit that this isn't true in general because
> such operations require the main program to recalculate and redraw the
> plot, which cannot happen in -persist mode because the main program
> has already exited.     As it happens, the wxt terminal back in version 4.4
> was an exception to this general case.  I guess people remember that 
> exception and want to generalize it to all current terminals.
> 
> That is, people expect this
> 
>     [1] gnuplot -persist -e "plot sinh(x); exit"
> 
> to act like this
> 
>     [2] gnuplot -e "plot sinh(x); pause mouse close; exit" &
> 
> The question is, should we continue pointing to the documented limitations
> of "persist", or should we change what persist does to match 
> people's
> expectation?  
> 
> So far as I know [2] works properly for the x11, wxt, and qt terminals
> under linux.  I don't know about MSWin (win) or OSX (aqua).
> 
> Assuming that [2] can be made to work correctly on all three of these
> platforms, should we reimplement "set term ... persist" and 
> "gnuplot -persist"
> to act like this instead of retaining the current implementation?
>


I have tested on windows (cvs changelog date is 2014-09-20)

gnuplot -e "plot sinh(x); pause mouse close; exit"


works as expected for wxt and windows terminal.
But for qt terminal, gnuplot exit immediately and we cannot use mouse.

For windows, there is not "fork" function so that persist mode works differently from other platforms.
In persist mode (case [1]), 
gnuplot session does not terminated so that we can use mouse for windows and wxt 
terminal. 

For qt terminal, perhaps gnuplot session is terminated but gnuplot_qt process exists.
We cannot use mouse for zoom for qt terminal.

Tatsuro