PyPlot.jl Empty window pops up when plotting

On @JeffBezanson's computer, whenever he makes a new plot with PyPlot, an empty window pops up.

Jan 21 '14 19:01 Keno

PyPlot.backend gives "Qt4Agg".

Jan 21 '14 20:01 JeffBezanson

Is this in IJulia, or in the terminal?

Jan 21 '14 20:01 stevengj

In the notebook. The plot actually does show up.

Jan 21 '14 20:01 Keno

Weird, I can't reproduce on my Mac. What OS?

Jan 21 '14 20:01 stevengj

Ubuntu I believe.

Jan 21 '14 20:01 Keno

Does it work if you do

using PyCall
pygui(:gtk)
using PyPlot

?

Jan 21 '14 21:01 stevengj

Yes! That gets rid of the empty windows.

Jan 21 '14 21:01 JeffBezanson

(Maybe I should use a PYCALL_GUI environment variable so that you can save this preference.)

@fperez, what backend does IPython default to for matplotlib on Linux distros?

Jan 21 '14 21:01 stevengj

I don't recall out of the box... It used to be GTK, I think (as that was the first one @jdh2358 wrote). @mdboom, do you know if that has changed recently?

Jan 22 '14 02:01 fperez

As of matplotlib 1.3.0, the default backend was changed to Qt4. More specifically, it sets the default backend to the first one that works in a list in this order:

    setupext.BackendMacOSX(),
    setupext.BackendQt4(),
    setupext.BackendGtk3Agg(),
    setupext.BackendGtk3Cairo(),
    setupext.BackendGtkAgg(),
    setupext.BackendTkAgg(),
    setupext.BackendWxAgg(),
    setupext.BackendGtk(),
    setupext.BackendAgg(),
    setupext.BackendCairo(),
    setupext.Windowing(),

Jan 22 '14 14:01 mdboom

@mdboom, is there something special you need to do to keep windows from popping up on Linux for inline plotting? We are initializing matplotlib with the Qt4Agg backend and just using switch_backend to switch to an Agg backend for inline plots, so that people can switch to Qt4 plotting at runtime if they wish. On MacOS and Windows, that seems to be enough to suppress plot windows.

(And why do you use Qt4 rather than Qt4Agg?)

Jan 22 '14 16:01 stevengj