Show plot until next update

[shloksobti]

Hi!
Is there a method to show a plot until it's updated? I don't want to have to press the "enter" key over again to update.

[alandefreitas]

If you're calling the drawing functions in a loop, just remove matplot::show() or ax->show() from your example. Or only call show() after the loop.

[alandefreitas]

An example: https://github.com/alandefreitas/matplotplusplus/blob/master/examples/geography/geoplot/geoplot_6.cpp

[shloksobti]

Thanks for the reply! I'm a little confused - removing [show()] doesn't show the plot, i.e. it disappears immediately. I want it to show until I update the plot.

[alandefreitas]

draw() and functions that call draw() only draw the plot. The show() function keeps the plot alive until there's some form of user interaction.

In more interactive applications, you usually keep updating the plot with draw() and then call show() only once in the end so that the program doesn't end and the plot doesn't disappear.

If you have a minimal example to replicate your problem, it might be easier to adapt that.

[shloksobti]

Thanks! I guess, I want some sort of a "live plotting". My application is plotting beliefs and I want to visualize how these beliefs change in an online inference setting.

If I show() only once at the end, it basically just shows the final belief. However, if I show() each time, it waits for the user to press Enter. One thing I can do is do all the plotting in a separate thread, but then I'd still need to somehow bypass the "press Enter to continue" step. Any thoughts?

[shloksobti]

For anyone else interested, just call draw() and then sleep() until you want to update the plot! Cheers!

[alandefreitas]

If I show() only once at the end

if I show() each time

Don't do any of these things. Don't only call show at the end. Don't call show each time.

Call draw while the program is running so you don't need user input AND call show at the end if you want the final results to be visible until there's some input.

These two functions serve different purposes. draw means "draw", but show means "draw and wait".

One thing I can do is do all the plotting in a separate thread,

The plots use a process pipe, so they are already happening in a separate thread. Just keep calling draw and let your executable run as usual.

Your plots will be visible in another window. You don't need to call sleep.

bypass the "press Enter to continue" step

That's exactly what draw() does