Re: Persistent confusion about gnuplot -persist

[Ethan A M. <sf...@us...>]

On Tuesday, 23 September, 2014 17:54:44 Tatsuro MATSUOKA wrote:
> 
> ----- 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.

Does "pause mouse close" work correctly from an interactive session using qt?     

	Ethan


> 
> 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.

Yes. That is the documented behavior.   But it seems to surprise some people.

> 
> Tatsuro