Develop Reference

Matplotlib canvas won't fit in wxpython panel

I'm trying to show an image inside a panel of a wxpython notebook page using matplotlib. It works perfectly using wx.StaticBitmap but I need to use matplotlib for image manipulation. The code gives this result:
The right panel is a terminal and sizes correctly. The left panel is where the image is meant to fit. The result of wx.lib.inspection is showing that the wxFigureCanvas minsize is (640, 480) but I don't understand why and can't find how to change that. I suspect it's the problem. The code (sorry, short as I could make it):
import cv2 as cv
import matplotlib.pyplot as plt
from matplotlib.figure import Figure
from matplotlib.backends.backend_wxagg import FigureCanvasWxAgg as FigureCanvas
import wx
import wx.lib.agw.aui as aui
class TopRight(wx.Panel):
def __init__(self, parent):
super(TopRight, self).__init__(parent)
self.term = wx.TextCtrl(self,
size=(200, 100),
style=wx.TE_MULTILINE|wx.TE_READONLY|wx.TE_RICH
)
self.term.SetDefaultStyle(wx.TextAttr(wx.GREEN))
self.term.SetBackgroundColour(wx.BLACK)
self.sizer = wx.BoxSizer(wx.VERTICAL)
self.sizer.Add(self.term, 1, wx.EXPAND)
self.SetSizer(self.sizer)
self.term.WriteText("hello")
self.term.Update
class TopLeft(wx.Panel):
def __init__(self, parent):
super(TopLeft , self).__init__(parent)
img_pth = "av_cat.png"
# Intitialise the matplotlib figure
self.figure = Figure()
# Create an axes, turn off the labels and add them to the figure
self.axes = plt.Axes(self.figure,[0,0,1,1])
self.axes.set_axis_off()
self.figure.add_axes(self.axes)
# Add the figure to the wxFigureCanvas
self.canvas = FigureCanvas(self, -1, self.figure)
# Sizer to contain the canvas
self.sizer = wx.BoxSizer(wx.VERTICAL)
self.sizer.Add(self.canvas, 1, wx.EXPAND|wx.ALL)
self.SetSizer(self.sizer)
# If there is an initial image, display it on the figure
if img_pth is not None:
self.setImage(img_pth)
def setImage(self, pathToImage):
# Load the image into matplotlib
image = cv.imread(pathToImage)
# Add the image to the figure and redraw the canvas.
self.axes.imshow(image)
self.canvas.draw()
class explorer_panel(wx.Panel):
def __init__(self, parent):
#Constructor
wx.Panel.__init__(self, parent)
topSplitter = wx.SplitterWindow(self)
image_panel = TopLeft(topSplitter)
terminal_panel = TopRight(topSplitter)
topSplitter.SplitVertically(image_panel, terminal_panel)
topSplitter.SetSashGravity(0.5)
sizer = wx.BoxSizer(wx.VERTICAL)
sizer.Add(topSplitter, 1, wx.EXPAND)
self.SetSizer(sizer)
class Main(wx.Frame):
def __init__(self):
wx.Frame.__init__(
self,
parent = None,
title = "Borges Infinite Image",
size = (600,300)
)
panel = wx.Panel(self)
notebook = wx.Notebook(panel)
explorer = explorer_panel(notebook)
notebook.AddPage(explorer, 'Explorer')
sizer = wx.BoxSizer(wx.VERTICAL)
sizer.Add(notebook, 1, wx.ALL|wx.EXPAND, 5)
panel.SetSizer(sizer)
if __name__ == "__main__":
app = wx.App()
frame = Main()
frame.Show()
import wx.lib.inspection as wxli
wxli.InspectionTool().Show()
app.MainLoop()

Update wxpython figure canvas with new figure

In a wxPython application I have an embedded a FigureCanvas with a matplotlib figure. I want to be able to switch the figure by loading a new one. However, the figure is not being updated.
Answers to similar topics suggests that panel.canvas.draw() and panel.Refresh() should do the trick, but I've also tried panel.Update() and panel.canvas.Refresh(). I fear that this only works if you want to redraw the canvas with the same figure?
So my question is: how do you replace the figure inside a canvas and make it update?
Below is a small (non-working) example. First a figure is loaded with a single axis. If you from the embedded shell type panel.LoadFigure() a new figure with 2x2 subplots is created and put into the canvas. But the new figure is not shown.
import numpy as np
import wx
from wx.py.shell import Shell
from matplotlib.backends.backend_wxagg import FigureCanvasWxAgg as FigureCanvas
import matplotlib.pyplot as plt
class ShellPanel(wx.Panel):
def __init__(self, parent):
wx.Panel.__init__(self, parent)
self.shell = Shell(self)
self.sizer = wx.BoxSizer(wx.VERTICAL)
self.sizer.Add(self.shell, 1, wx.GROW)
self.SetSizer(self.sizer)
self.Layout()
self.Fit()
class FigurePanel(wx.Panel):
def __init__(self, parent):
wx.Panel.__init__(self, parent)
self.parent = parent
self.sizer = wx.BoxSizer(wx.VERTICAL)
self.figure, ax = plt.subplots()
self.canvas = FigureCanvas(self, -1, self.figure)
self.shellpanel = ShellPanel(self)
s1 = wx.BoxSizer(wx.VERTICAL)
s1.Add(self.canvas, 0, wx.GROW)
s1.Add(self.shellpanel, 1 , wx.EXPAND)
self.sizer.Add(s1, 5, wx.GROW)
self.SetSizer(self.sizer)
self.Layout()
self.Fit()
def LoadFigure(self):
self.figure, ax = plt.subplots(2, 2)
self.canvas.draw()
self.Refresh()
class FigureFrame(wx.Frame):
def __init__(self, parent, id, title, size):
wx.Frame.__init__(self, parent, id, title, size=size)
if __name__ == "__main__":
app = wx.App(False)
fr = FigureFrame(None, -1, title='Figure Loader', size=(wx.DisplaySize()[0]/2, wx.DisplaySize()[1]*3/4))
panel = FigurePanel(fr)
fr.Show()
app.MainLoop()

Is there any reason you are trying to create a new Figure and not simply new Axes on the already defined Figure?
I would write your code like so:
def LoadFigure(self):
self.figure.clf() # clear current figure
# add arbitrary number of new Axes
self.figure.add_subplot(221)
self.figure.add_subplot(222)
self.figure.add_subplot(223)
self.figure.add_subplot(224)
self.canvas.draw() # refresh canvas
EDIT: following your comment, I think the problem is that you're creating a new figure, but your Canvas is still referencing the old one. I don't know if you can change that directly in the FigureCanvas properties, maybe someone with more experience can provide a better answer. For the moment, I would Destroy the previous canvas, and create a new FigureCanvas object with your new figure.
def LoadFigure(self):
self.figure, ax = plt.subplots(2, 2)
self.canvas.Destroy()
self.canvas = FigureCanvas(self, -1, self.figure)
self.canvas.draw()

Try using the Figure itself to make your figure, not pyplot. It has usually worked for me because it gives you more room to improvise.
#!/usr/bin/python
# -*- coding: utf-8 -*-
import numpy as np
import wx
from wx.py.shell import Shell
from matplotlib.figure import Figure
from matplotlib.backends.backend_wxagg import FigureCanvasWxAgg as FigureCanvas
import matplotlib.pyplot as plt
class ShellPanel(wx.Panel):
def __init__(self, parent):
wx.Panel.__init__(self, parent)
self.shell = Shell(self)
self.sizer = wx.BoxSizer(wx.VERTICAL)
self.sizer.Add(self.shell, 1, wx.GROW)
self.SetSizer(self.sizer)
self.Layout()
self.Fit()
class FigurePanel(wx.Panel):
def __init__(self, parent):
wx.Panel.__init__(self, parent)
self.parent = parent
self.sizer = wx.BoxSizer(wx.VERTICAL)
self.figure = Figure(figsize = (8,6.1), dpi =60)
self.ax = self.figure.add_subplot(1,1,1)
self.enlarged_figure = Figure(figsize = (8,6.1), dpi = 100)
self.ax2 = self.enlarged_figure.add_subplot(2,1,2)
self.canvas = FigureCanvas(self, -1, self.figure)
self.canvas.Show()
self.enlarged_canvas = FigureCanvas(self,-1,self.enlarged_figure)
self.enlarged_canvas.Show()
self.shellpanel = ShellPanel(self)
s1 = wx.BoxSizer(wx.VERTICAL)
s1.Add(self.canvas, 0, wx.GROW)
s1.Add(self.shellpanel, 1 , wx.EXPAND)
self.sizer.Add(s1, 5, wx.GROW)
self.SetSizer(self.sizer)
self.Layout()
self.Fit()
def LoadFigure(self):
self.figure, ax = plt.subplots(2, 2)
self.canvas.draw()
self.Refresh()
class FigureFrame(wx.Frame):
def __init__(self, parent, id, title, size):
wx.Frame.__init__(self, parent, id, title, size=size)
if __name__ == "__main__":
app = wx.App(False)
fr = FigureFrame(None, -1, title='Figure Loader', size=(wx.DisplaySize()[0]/2, wx.DisplaySize()[1]*3/4))
panel = FigurePanel(fr)
fr.Show()
app.MainLoop()
In the shell type in 'panel.LoadFigure()' and the new figure will show up very quickly and then disappear. Then type 'panel.canvas.draw()' and the new figure will be there. Then type 'panel.LoadFigure()' to load the old figure back. Repeat.
I don't know why the figure remains hidden after the MainLoop() continues but this is sort of a quick fix to your problem.

WXPython with MatPlotLib

I am trying to use MatPlotLib with WXPython. I find a nice example from http://www.cs.colorado.edu/~kena/classes/5448/s11/presentations/pearse.pdf
because it show how to use 2 panels and it is well explained how to embed matplotlib. But I think it is missing some part, because the graphic isn't being initialized.
How can I fix that?
import wx
import numpy
import matplotlib
from matplotlib.figure import Figure
from matplotlib.backends.backend_wxagg import FigureCanvasWxAgg as FigureCanvas
class TestFrame(wx.Frame):
def __init__(self,parent,title):
wx.Frame.__init__(self,parent,title=title,size=(500,500))
self.sp = wx.SplitterWindow(self)
self.p1 = wx.Panel(self.sp, style=wx.SUNKEN_BORDER)
self.p2 = wx.Panel(self.sp, style=wx.SUNKEN_BORDER)
self.sp.SplitVertically(self.p1,self.p2,100)
self.statusbar = self.CreateStatusBar()
self.statusbar.SetStatusText('Oi')
class p1(wx.Panel):
def __init__(self, parent):
wx.Panel.__init__(self, parent,-1,size=(50,50))
self.figure = matplotlib.figure.Figure()
self.axes = self.figure.add_subplot(111)
t = numpy.arange(0.0,10,1.0)
s = [0,1,0,1,0,2,1,2,1,0]
self.y_max = 1.0
self.axes,plot(t,s)
self.canvas = FigureCanvas(self,-1,self.figure)
app = wx.App(redirect=False)
frame = TestFrame(None, 'Hello World!')
frame.Show()
app.MainLoop()
Thanks.

You made class p1 with matplot but you didn't use it in TestFrame.
I changed some names to make it more clear
import wx
import numpy
import matplotlib
from matplotlib.figure import Figure
from matplotlib.backends.backend_wxagg import FigureCanvasWxAgg as FigureCanvas
class TestFrame(wx.Frame):
def __init__(self,parent,title):
wx.Frame.__init__(self,parent,title=title,size=(500,500))
self.sp = wx.SplitterWindow(self)
self.p1 = wx.Panel(self.sp, style=wx.SUNKEN_BORDER)
self.p2 = MatplotPanel(self.sp)
self.sp.SplitVertically(self.p1,self.p2,100)
self.statusbar = self.CreateStatusBar()
self.statusbar.SetStatusText('Oi')
class MatplotPanel(wx.Panel):
def __init__(self, parent):
wx.Panel.__init__(self, parent,-1,size=(50,50))
self.figure = Figure()
self.axes = self.figure.add_subplot(111)
t = numpy.arange(0.0,10,1.0)
s = [0,1,0,1,0,2,1,2,1,0]
self.y_max = 1.0
self.axes.plot(t,s)
self.canvas = FigureCanvas(self,-1,self.figure)
app = wx.App(redirect=False)
frame = TestFrame(None, 'Hello World!')
frame.Show()
app.MainLoop()
see also (as example) my answer to how to combine wxPython, matplotlib and Pyopengl
EDIT:
MatplotPanel with NavigationToolbar and wx.Button to change plot.
EDIT: 2022.01.03
As #Samuel said in comment: newer matplotlib needs NavigationToolbar2WxAgg instead of NavigationToolbar2Wx. See also matplotlib doc: Embedding in wx #2
# older matplotlib
#from matplotlib.backends.backend_wxagg import NavigationToolbar2Wx as NavigationToolbar
# newer matplotlib
from matplotlib.backends.backend_wxagg import NavigationToolbar2WxAgg as NavigationToolbar
class MatplotPanel(wx.Panel):
def __init__(self, parent):
wx.Panel.__init__(self, parent,-1,size=(50,50))
self.sizer = wx.BoxSizer(wx.VERTICAL)
self.SetSizer(self.sizer)
self.figure = Figure()
self.axes = self.figure.add_subplot(111)
self.canvas = FigureCanvas(self, -1, self.figure)
self.toolbar = NavigationToolbar(self.canvas)
self.button = wx.Button(self, -1, "Change plot")
self.button.Bind(wx.EVT_BUTTON, self.changePlot)
self.sizer.Add(self.toolbar, 0, wx.EXPAND)
self.sizer.Add(self.button, 0, wx.EXPAND)
self.sizer.Add(self.canvas, 1, wx.LEFT | wx.TOP | wx.GROW)
self.drawSin()
self.current_draw = 'sin'
# self.drawLines()
def changePlot(self, event):
if self.current_draw == 'sin' :
self.drawLines()
self.current_draw = 'lines'
else:
self.drawSin()
self.current_draw = 'sin'
self.Layout()
def drawLines(self):
x = numpy.arange(0.0,10,1.0)
y = [0,1,0,1,0,2,1,2,1,0]
self.axes.clear()
self.axes.plot(x, y)
def drawSin(self):
x = numpy.arange(0.0,10,0.1)
y = numpy.sin(x)
self.axes.clear()
self.axes.plot(x, y)

wxpython + matplotlib: autoresizing a matplotlib figure

This python program plots a figure in a wxpython window.
How can I change the program so that:
the figure resizes when I resize the window
the main window cannot be resized smaller than a particular dimension? (say, half the default size of the window)
.
# adapted from:
# http://wiki.wxpython.org/Getting%20Started
# http://www.cs.colorado.edu/~kena/classes/5448/s11/presentations/pearse.pdf
import wx
import pylab as pl
import matplotlib
from matplotlib.backends.backend_wxagg import FigureCanvasWxAgg as FigureCanvas
class GUIPanel(wx.Panel):
def __init__(self, parent):
wx.Panel.__init__(self, parent)
self.parent = parent
# create some sizers
sizer = wx.BoxSizer(wx.VERTICAL)
# A button
self.button =wx.Button(self, label="Tada!")
self.Bind(wx.EVT_BUTTON, self.OnClick,self.button)
# put up a figure
self.figure = pl.figure()
self.axes = self.drawplot(self.figure)
self.canvas = FigureCanvas(self, -1, self.figure)
sizer.Add(self.canvas, 0, wx.ALIGN_CENTER|wx.ALL)
sizer.Add(self.button, 0, wx.ALIGN_CENTER|wx.ALL)
self.SetSizerAndFit(sizer)
def log(self, fmt, *args):
print (fmt % args)
def OnClick(self,event):
self.log("button clicked, id#%d\n", event.GetId())
def drawplot(self, fig):
ax = fig.add_subplot(1,1,1)
t = pl.arange(0,1,0.001)
ax.plot(t,t*t)
ax.grid()
return ax
app = wx.App(False)
frame = wx.Frame(None)
panel = GUIPanel(frame)
frame.Fit()
frame.Center()
frame.Show()
app.MainLoop()

1) Modify the way you setup your sizer to this:
sizer.Add(self.canvas, 1, wx.EXPAND | wx.ALL)
Here is method reference. It is also helpful to install and use wxPython Demo. Sizers are covered nicely there. BTW: wx.ALL is useless unless you specify border.
2) And add this to your frame setup after frame.Show():
size = frame.GetSize()
frame.SetMinSize((size[0] / 2, size[1] / 2))

selecting points from a graph matplotlib

At the moment I have a scatter graph which I can zoom in, move around etc.
What I also want to do is be able to select a certain number of points on the graph, then store the selected points in an array.
Is there any special function in matplotlib I can use?
Any help will be greatly appreciated
My code
import os
import wx
import numpy as nump
import matplotlib
matplotlib.use('WXAgg')
import matplotlib.figure as fg
import matplotlib.backends.backend_wxagg as wxagg
class MyFrame(wx.Frame):
def __init__(self):
wx.Frame.__init__(self, None, -1, 'Title')
self.create_main_panel()
self.draw_figure()
def create_main_panel(self):
self.panel = wx.Panel(self)
self.dpi = 100
self.fig = fg.Figure((5.0, 4.0), dpi=self.dpi)
self.canvas = wxagg.FigureCanvasWxAgg(self.panel, -1, self.fig)
self.axes = self.fig.add_subplot(111)
self.toolbar = wxagg.NavigationToolbar2WxAgg(self.canvas)
self.vbox = wx.BoxSizer(wx.VERTICAL)
self.vbox.Add(self.canvas, 1, wx.LEFT | wx.TOP | wx.GROW)
self.vbox.AddSpacer(25)
self.vbox.Add(self.toolbar, 0, wx.EXPAND)
self.panel.SetSizer(self.vbox)
self.vbox.Fit(self)
def draw_figure(self):
self.axes.clear()
x, y = [2,3,4,5]
self.axes.scatter(x, y)
self.canvas.draw()
def on_exit(self, event):
self.Destroy()
if __name__ == '__main__':
app = wx.PySimpleApp()
app.frame = MyFrame()
app.frame.Show()
app.MainLoop()

The code below provides a possible solution. The basic method may be summarized as follows:
One attaches a handler for pick_event that keeps appending the picked data indices to a list self._picked_indices.
A key_press_event handler clears the self._picked_indices list whenever the user presses the escape key.
The method MyFrame.picked_points returns a list of coordinates of currently selected points. This method returns None if no points have been selected yet (you can modify it to return an empty list in this case if that is more convenient).
This way you can keep selecting points by clicking on them. But if you want to start over again, just press escape and start picking again.
#! /usr/bin/env python
import os
import wx
import numpy as nump
import matplotlib
matplotlib.use('WXAgg')
import matplotlib.figure as fg
import matplotlib.backends.backend_wxagg as wxagg
class MyFrame(wx.Frame):
def __init__(self):
wx.Frame.__init__(self, None, -1, 'Title')
self.create_main_panel()
self.draw_figure()
self._is_pick_started = False
self._picked_indices = None
def create_main_panel(self):
self.panel = wx.Panel(self)
self.dpi = 100
self.fig = fg.Figure((5.0, 4.0), dpi=self.dpi)
self.canvas = wxagg.FigureCanvasWxAgg(self.panel, -1, self.fig)
self.axes = self.fig.add_subplot(111)
self.toolbar = wxagg.NavigationToolbar2WxAgg(self.canvas)
self.vbox = wx.BoxSizer(wx.VERTICAL)
self.vbox.Add(self.canvas, 1, wx.LEFT | wx.TOP | wx.GROW)
self.vbox.AddSpacer(25)
self.vbox.Add(self.toolbar, 0, wx.EXPAND)
self.panel.SetSizer(self.vbox)
self.vbox.Fit(self)
self.fig.canvas.mpl_connect('pick_event', self.on_pick)
self.fig.canvas.mpl_connect('key_press_event', self.on_key)
def draw_figure(self):
self.axes.clear()
self._x_data, self._y_data = [[2,3], [4,5]]
self.axes.scatter(self._x_data, self._y_data, picker=5)
self.canvas.draw()
def on_exit(self, event):
self.Destroy()
def picked_points(self):
if self._picked_indices is None:
return None
else:
return [ [self._x_data[i], self._y_data[i]]
for i in self._picked_indices ]
def on_pick(self, event):
if not self._is_pick_started:
self._picked_indices = []
self._is_pick_started = True
for index in event.ind:
if index not in self._picked_indices:
self._picked_indices.append(index)
print self.picked_points()
def on_key(self, event):
"""If the user presses the Escape key then stop picking points and
reset the list of picked points."""
if 'escape' == event.key:
self._is_pick_started = False
self._picked_indices = None
return
if __name__ == '__main__':
app = wx.PySimpleApp()
app.frame = MyFrame()
app.frame.Show()
app.MainLoop()