topic Re: matplotlib.pyplot.show() crashes ArcGIS in Python Questions

matplotlib.pyplot.show() crashes ArcGIS

CanZhang — Mon, 04 Jan 2016 10:13:59 GMT

Hello everyone!

I'm creating a customizing tools in arcgis. I want to show some diagrams in arcgis, which made by matplotlib.

Everything works fine, the diagram kann even be saved in the right way, except when I show the plot through plt.show(), ArcGIS hangs and I have to force it to close with Task Manager.

Changing plt.show() to plt.show(block=False) should make the plot non-blocking, but this crashes ArcMap either, with a Runtime Error.

I am working with Windows 7 and ArcGIS 10.1.

The codes are something like:

import ConversionUtils

import arcpy

from arcpy import env

import matplotlib.pyplot as plt

xLabelName = ConversionUtils.gp.GetParameterAsText(0)

yLabelName = ConversionUtils.gp.GetParameterAsText(1)

Titel = ConversionUtils.gp.GetParameterAsText(2)

fig = plt.figure() plt.plot(range(10), range(10))

plt.xlabel(xLabelName, fontsize = 14)

plt.ylabel(yLabelName, fontsize = 14)

plt.title(str(Titel), fontsize = 16)

plt.grid()

plt.savefig('abc.png')

plt.show()

Because matplotlib uses TKinter by default, so the window pop up from plt.show() crashes ArcGIS.

The problem has been bothering me for days. I will greatly appreciate any ideas on how can I solve this Problem.

Thank you.

Re: matplotlib.pyplot.show() crashes ArcGIS

DanPatterson_Retired — Mon, 04 Jan 2016 10:49:56 GMT

It will probably remain so, since no one can replicate the problem with only partial code.

Re: matplotlib.pyplot.show() crashes ArcGIS

CanZhang — Mon, 04 Jan 2016 11:01:18 GMT

I have complemented the code.

Re: matplotlib.pyplot.show() crashes ArcGIS

DanPatterson_Retired — Sun, 12 Dec 2021 00:48:34 GMT

So the trick is to track down the source of the error. I edited the code to simplify it.

import ConversionUtils
import arcpy 
from arcpy import env 
import matplotlib.pyplot as plt
xLabelName = "x label"
yLabelName = "y_label"
title = "Title"
fig = plt.figure()
plt.plot(range(10), range(10))
plt.xlabel(xLabelName, fontsize = 14) 
plt.ylabel(yLabelName, fontsize = 14) 
plt.title(str(title), fontsize = 16)
plt.grid() 
plt.savefig("f:/test/abc.png") 
plt.show()

Basically I got rid of all that conversion stuff and tried to get output as a graph (see image) and as a file (see file).

It works...ergo...your problem is with your inputs using that ConversionUtils stuff. At least your have a start point.

Re: matplotlib.pyplot.show() crashes ArcGIS

CanZhang — Mon, 04 Jan 2016 11:24:44 GMT

Yes, as you've tried, it works also fine only with python IDLE.

Because I use the code as the source of a customizing tool, so I need using that ConversionUtils). The problem is : the matplotlib utilizes Tkinter in it's backend. I've had problems running Tkinter windows from within ArcMap.

Re: matplotlib.pyplot.show() crashes ArcGIS

DanPatterson_Retired — Mon, 04 Jan 2016 11:28:01 GMT

Yes, Tkinter will cause crashes, just google " tkinter arcmap crash " for some examples.

There are also posts for alternatives, for example python addins

python addin - Creating Tkinter dialog box in arcpy? - Geographic Information Systems Stack Exchange

But practically, you would be better off, using a conventional or python toolbox to get your input parameters rather than reinventing the wheel in a different dialog, if you intend to use this in arcmap

Re: matplotlib.pyplot.show() crashes ArcGIS

CanZhang — Mon, 04 Jan 2016 16:05:09 GMT

My input parameters are using a conventional GUI through ConversionUtils.gp.GetParameterAsText.

The Tkinter window is a output window, which pop up through plt.show().

After I run the tool/script, it shows an extra window with the plot diagram. Just like the output in IDLE.

Then I want to use this output window. After I usethe Pan/Zoom button, then click the save button in this window, it crashes arcgis. The diagram cannot be saved with this button, but I want to...

Re: matplotlib.pyplot.show() crashes ArcGIS

DanPatterson_Retired — Mon, 04 Jan 2016 16:17:28 GMT

Sorry...the window I showed works for me, don't know why yours doesn't. Using Windows 10, ArcMap 10.3.1, tested in python 3.4.x and 2.7.x

Re: matplotlib.pyplot.show() crashes ArcGIS

CanZhang — Mon, 04 Jan 2016 16:31:21 GMT

It doesn't work by me..I have to force it to close arcgis with Task Manager.

but thank you all the way.

Re: matplotlib.pyplot.show() crashes ArcGIS

DanPatterson_Retired — Tue, 05 Jan 2016 06:35:31 GMT

you might want to try it without the ConversionUtils module and either develop your app so that arcmap doesn't need to be open

Re: matplotlib.pyplot.show() crashes ArcGIS

JamesCrandall — Tue, 05 Jan 2016 14:50:07 GMT

I didn't see it in your code example (or in Dan' either), but you should close the plt --- include this line after the plt.show():

plt.close()

See if that stops the instability you are experiencing.

Re: matplotlib.pyplot.show() crashes ArcGIS

JamesCrandall — Sun, 12 Dec 2021 00:48:36 GMT

As an alternative, why not just let the default image viewer open the plot?

import os
import matplotlib.pyplot as plt

def plotthegraph():

    xLabelName = "x label" 
    yLabelName = "y_label" 
    title = "Title" 
    fig = plt.figure() 
    plt.plot(range(10), range(10)) 
    plt.xlabel(xLabelName, fontsize = 14) 
    plt.ylabel(yLabelName, fontsize = 14) 
    plt.title(str(title), fontsize = 16) 
    plt.grid() 
    plt.savefig(r'H:\abc.png')
    plt.close()
    os.system(r'H:\abc.png') #this should allow the installed image viewer to open the png

Re: matplotlib.pyplot.show() crashes ArcGIS

DanPatterson_Retired — Tue, 05 Jan 2016 15:53:29 GMT

James, I think the problem he is having is that he has an extra instance of a Tkinter window opening through some means. They don't behave with ArcMap, but I have had no problem with matplotlib figures opening ... I can even flip back and forth to the graph window and arcmap. If you try to have other Tk dialogs open, there are "issues" which for some undocumented reasons, ArcMap doesn't behave nicely in the presence of Tkinter even though it is distributed with python. There are work arounds, but they are akin to getting a car to move with square wheels.

Re: matplotlib.pyplot.show() crashes ArcGIS

JamesCrandall — Tue, 05 Jan 2016 16:03:55 GMT

I've seen weirdness at times too. But if you do not instantiate plt.show(), simply save the fig, close it and then just allow os.system to open it using whatever default Windows application that typically views .png files to open it should remove the instability issues because a Tkinter window is not being used.

Re: matplotlib.pyplot.show() crashes ArcGIS

CanZhang — Tue, 05 Jan 2016 16:10:22 GMT

Hi James, right, this is maybe an alternativ solution, so that the TK window won't show up in arcgis.

ps: plt.close() doesn't work, because plt.show() will suspend the process/script, until man close the window manual.

Re: matplotlib.pyplot.show() crashes ArcGIS

JamesCrandall — Tue, 05 Jan 2016 16:21:12 GMT

You definitely want to include plt.close() after you have finished with writing the plot to a file!!! Google it