Dynamically update multiple axis in matplotlib - python

I want to display sensor data on a PyQT GUI with a matplotlib animation.
I already have a working Plot which gets updates every time I receive new sensor value from an external source with this code:
def __init__(self):
self.fig = Figure(figsize=(width, height), dpi=dpi)
self.axes = self.fig.add_subplot(111)
self.axes.grid()
self.xdata = []
self.ydata = []
self.entry_limit = 50
self.line, = self.axes.plot([0], [0], 'r')
def update_figure_with_new_value(self, xval: float, yval: float):
self.xdata.append(xval)
self.ydata.append(yval)
if len(self.xdata) > self.entry_limit:
self.xdata.pop(0)
self.ydata.pop(0)
self.line.set_data(self.xdata, self.ydata)
self.axes.relim()
self.axes.autoscale_view()
self.fig.canvas.draw()
self.fig.canvas.flush_events()
I want now to extend the plot to show another data series with the same x-axis. I tried to achieve this with the following additions to the init-code above:
self.axes2 = self.axes.twinx()
self.y2data = []
self.line2, = self.axes2.plot([0], [0], 'b')
and in the update_figure_with_new_value() function (for test purpose I just tried to add 1 to yval, I will extend the params of the function later):
self.y2data.append(yval+1)
if len(self.y2data) > self.entry_limit:
self.y2data.pop(0)
self.line2.set_data(self.xdata, self.ydata)
self.axes2.relim()
self.axes2.autoscale_view()
But instead of getting two lines in the plot which should have the exact same movement but just shifted by one I get vertical lines for the second plot axis (blue). The first axis (red) remains unchanged and is ok.
How can I use matplotlib to update multiple axis so that they display the right values?
I'm using python 3.4.0 with matplotlib 2.0.0.

Since there is no minimal example available, it's hard to tell the reason for this undesired behaviour. In principle ax.relim() and ax.autoscale_view() should do what you need.
So here is a complete example which works fine and updates both scales when being run with python 2.7, matplotlib 2.0 and PyQt4:
import numpy as np
import matplotlib.pyplot as plt
from PyQt4 import QtGui, QtCore
from matplotlib.figure import Figure
from matplotlib.backends.backend_qt4agg import FigureCanvasQTAgg as FigureCanvas
from matplotlib.backends.backend_qt4agg import NavigationToolbar2QT as NavigationToolbar
class Window(QtGui.QMainWindow):
def __init__(self):
QtGui.QMainWindow.__init__(self)
self.widget = QtGui.QWidget()
self.setCentralWidget(self.widget)
self.widget.setLayout(QtGui.QVBoxLayout())
self.widget.layout().setContentsMargins(0,0,0,0)
self.widget.layout().setSpacing(0)
self.fig = Figure(figsize=(5,4), dpi=100)
self.axes = self.fig.add_subplot(111)
self.axes.grid()
self.xdata = [0]
self.ydata = [0]
self.entry_limit = 50
self.line, = self.axes.plot([], [], 'r', lw=3)
self.axes2 = self.axes.twinx()
self.y2data = [0]
self.line2, = self.axes2.plot([], [], 'b')
self.canvas = FigureCanvas(self.fig)
self.canvas.draw()
self.nav = NavigationToolbar(self.canvas, self.widget)
self.widget.layout().addWidget(self.nav)
self.widget.layout().addWidget(self.canvas)
self.show()
self.ctimer = QtCore.QTimer()
self.ctimer.timeout.connect(self.update)
self.ctimer.start(150)
def update(self):
y = np.random.rand(1)
self.update_figure_with_new_value(self.xdata[-1]+1,y)
def update_figure_with_new_value(self, xval,yval):
self.xdata.append(xval)
self.ydata.append(yval)
if len(self.xdata) > self.entry_limit:
self.xdata.pop(0)
self.ydata.pop(0)
self.y2data.pop(0)
self.line.set_data(self.xdata, self.ydata)
self.axes.relim()
self.axes.autoscale_view()
self.y2data.append(yval+np.random.rand(1)*0.17)
self.line2.set_data(self.xdata, self.y2data)
self.axes2.relim()
self.axes2.autoscale_view()
self.fig.canvas.draw()
self.fig.canvas.flush_events()
if __name__ == "__main__":
qapp = QtGui.QApplication([])
a = Window()
exit(qapp.exec_())
You may want to test this and report back if it is working or not.

Related

Python qt5 matplotlb canvas animation with manual blit

So I'd like to integrate a matplotlib canvas in qt5 with manual blit.
I've found this thread:
Fast Live Plotting in Matplotlib / PyPlot
and the voted answer seems pretty nice however I need it in a qt5 window...
So I have tried to mash the code above together with the matplotlib qt5 tutorial into one script. https://matplotlib.org/gallery/user_interfaces/embedding_in_qt5_sgskip.html
It kinda works, however the animation only works when using the pan/zoom and the background is black :D and if blit is set to false it doesnt even draw...
If somebody could help me that would be amazing :) Its hilariously broken
from __future__ import unicode_literals
import random
import time
import matplotlib
from PyQt5.QtWidgets import QSizePolicy, QApplication, QWidget, QVBoxLayout
from matplotlib import pyplot as plt
import sys
import matplotlib
matplotlib.use('Qt5Agg')
from matplotlib.animation import FuncAnimation
from matplotlib.backends.backend_qt5agg import NavigationToolbar2QT as NavigationToolbar
from matplotlib.backends.backend_qt5agg import FigureCanvasQTAgg as FigureCanvas
import numpy as np
class MyMplCanvas(FigureCanvas):
# Ultimately, this is a QWidget (as well as a FigureCanvasAgg, etc.).
def __init__(self, parent=None, width=5, height=4, dpi=100):
self.fig = plt.figure()
FigureCanvas.__init__(self, self.fig)
self.setParent(parent)
FigureCanvas.setSizePolicy(self,
QSizePolicy.Expanding,
QSizePolicy.Expanding)
FigureCanvas.updateGeometry(self)
self.x = np.linspace(0, 50., num=100)
self.X, self.Y = np.meshgrid(self.x, self.x)
# self.fig = plt.figure()
self.ax1 = self.fig.add_subplot(2, 1, 1)
self.ax2 = self.fig.add_subplot(2, 1, 2)
self.img = self.ax1.imshow(self.X, vmin=-1, vmax=1, interpolation="None", cmap="RdBu")
self.line, = self.ax2.plot([], lw=3)
self.text = self.ax2.text(0.8, 0.5, "")
self.ax2.set_xlim(self.x.min(), self.x.max())
self.ax2.set_ylim([-1.1, 1.1])
self.t_start = time.time()
self.k = 0.
#self.fig.canvas.draw() # note that the first draw comes before setting data
#self.update(blit=False)
anim = FuncAnimation(self.fig, self.update, interval=20)
def update(self, blit=True):
if blit:
# cache the background
self.axbackground = self.fig.canvas.copy_from_bbox(self.ax1.bbox)
self.ax2background = self.fig.canvas.copy_from_bbox(self.ax2.bbox)
self.img.set_data(np.sin(self.X / 3. + self.k) * np.cos(self.Y / 3. + self.k))
self.line.set_data(self.x, np.sin(self.x / 3. + self.k))
self.k += 0.11
if blit:
# restore background
self.fig.canvas.restore_region(self.axbackground)
self.fig.canvas.restore_region(self.ax2background)
# redraw just the points
self.ax1.draw_artist(self.img)
self.ax2.draw_artist(self.line)
self.ax2.draw_artist(self.text)
# fill in the axes rectangle
self.fig.canvas.blit(self.ax1.bbox)
self.fig.canvas.blit(self.ax2.bbox)
# in this post http://bastibe.de/2013-05-30-speeding-up-matplotlib.html
# it is mentionned that blit causes strong memory leakage.
# however, I did not observe that.
else:
# redraw everything
self.fig.canvas.draw()
# self.fig.canvas.flush_events()
# alternatively you could use
# plt.pause(0.000000000001)
# however plt.pause calls canvas.draw(), as can be read here:
# http://bastibe.de/2013-05-30-speeding-up-matplotlib.html
class PlotDialog(QWidget):
def __init__(self):
QWidget.__init__(self)
self.plot_layout = QVBoxLayout(self)
self.plot_canvas = MyMplCanvas(self, width=5, height=4, dpi=100)
self.navi_toolbar = NavigationToolbar(self.plot_canvas, self)
self.plot_layout.addWidget(self.plot_canvas)
self.plot_layout.addWidget(self.navi_toolbar)
if __name__ == "__main__":
app = QApplication(sys.argv)
dialog0 = PlotDialog()
dialog0.show()
sys.exit(app.exec_())

matplotlib.widgets.TextBox interaction is slow when figure contains several subplots

Below is python code to demonstrate the problem.
If there are 2 rows and 2 columns of images, for example, typing/erasing in the textbox is reasonably fast. However, if there are 5 rows and 5 columns, typing/erasing in the textbox is quite slow. If the xticks and yticks are drawn, interaction is even slower. So, it seems as if the entire figure is redrawn after every keystroke.
Is there a solution for this (apart from putting the textbox on a separate figure)?
(My development platform is MacOS Mojave, Python 3.7.5.)
import numpy as np
import matplotlib.pyplot as plt
import matplotlib.gridspec as gridspec
from matplotlib.widgets import TextBox
class Textbox_Demo(object):
def __init__(self):
self.fig = plt.figure(figsize=(8,8))
self.string = 'label'
self.rows = 5 # reducing rows speeds up textbox interaction
self.cols = 5 # reducing cols speeds up textbox interaction
self.plot_count = self.rows * self.cols
self.gs = gridspec.GridSpec(self.rows, self.cols,
left=0.05, right=1-0.02, top=1-.02, bottom=0.10, wspace=0.3, hspace=0.4)
for k in range(self.plot_count):
ax = self.fig.add_subplot(self.gs[k])
#ax.set_xticks([]) # showing axes slows textbox interaction
#ax.set_yticks([]) # showing axes slows textbox interaction
data = np.atleast_2d(np.sin(np.linspace(1,255,255) * 50))
ax.imshow(data, aspect="auto", cmap='ocean')
# this is the user-input textbox
tb_axis = plt.axes([0.125, 0.02, 0.8, 0.05])
self.tb = TextBox(tb_axis, 'Enter label:', initial=self.string, label_pad=0.01)
self.tb.on_submit(self.on_submit)
plt.show()
def on_submit(self, text):
pass
if __name__ == "__main__":
Textbox_Demo()
Matplotlib's TextBox is inherently slow, because it uses the drawing tools provided by matplotlib itself and hence redraws the complete figure upon changes.
I would propose to use a text box of a GUI kit instead. For example for PyQt this might look like:
import numpy as np
import sys
from matplotlib.backends.backend_qt5agg import (
FigureCanvas, NavigationToolbar2QT as NavigationToolbar)
from matplotlib.backends.qt_compat import QtCore, QtWidgets
import matplotlib.gridspec as gridspec
from matplotlib.figure import Figure
class Textbox_Demo(QtWidgets.QMainWindow):
def __init__(self):
super().__init__()
self._main = QtWidgets.QWidget()
self.setCentralWidget(self._main)
layout = QtWidgets.QVBoxLayout(self._main)
layout.setContentsMargins(0,0,0,0)
layout.setSpacing(0)
self.fig = Figure(figsize=(8,8))
self.canvas = FigureCanvas(self.fig)
layout.addWidget(self.canvas)
self.addToolBar(NavigationToolbar(self.canvas, self))
self._textwidget = QtWidgets.QWidget()
textlayout = QtWidgets.QHBoxLayout(self._textwidget)
self.textbox = QtWidgets.QLineEdit(self)
self.textbox.editingFinished.connect(self.on_submit)
# or, if wanting to have changed apply directly:
# self.textbox.textEdited.connect(self.on_submit)
textlayout.addWidget(QtWidgets.QLabel("Enter Text: "))
textlayout.addWidget(self.textbox)
layout.addWidget(self._textwidget)
self.fill_figure()
def fill_figure(self):
self.string = 'label'
self.rows = 5 # reducing rows speeds up textbox interaction
self.cols = 5 # reducing cols speeds up textbox interaction
self.plot_count = self.rows * self.cols
self.gs = gridspec.GridSpec(self.rows, self.cols,
left=0.05, right=1-0.02, top=1-.02, bottom=0.10, wspace=0.3, hspace=0.4)
for k in range(self.plot_count):
ax = self.fig.add_subplot(self.gs[k])
#ax.set_xticks([]) # showing axes slows textbox interaction
#ax.set_yticks([]) # showing axes slows textbox interaction
data = np.atleast_2d(np.sin(np.linspace(1,255,255) * 50))
ax.imshow(data, aspect="auto", cmap='ocean')
def on_submit(self):
text = self.textbox.text()
print(text)
pass
if __name__ == "__main__":
qapp = QtWidgets.QApplication(sys.argv)
app = Textbox_Demo()
app.show()
qapp.exec_()

How to effectively redraw multiple matplotlib plots with blit

I'm using matplotlib with pyqt5 to draw data into 3 axes, and than user can make selection in one plot that will be shown in other two plots too. Since I'm working with big data (up to 10 millions of points), drawing selection could be slow, especially when I need to draw to scatterplot.
I am trying to use matplotlib blit function, but have some issues with result. Here is minimum simple example.
import matplotlib
matplotlib.use('Qt5Agg')
import numpy as np
import sys
from matplotlib.backends.qt_compat import QtCore, QtWidgets
from matplotlib.backends.backend_qt5agg import (FigureCanvas, NavigationToolbar2QT as NavigationToolbar)
from matplotlib.figure import Figure
class ApplicationWindow(QtWidgets.QMainWindow):
def __init__(self):
super().__init__()
self._main = QtWidgets.QWidget()
self.setCentralWidget(self._main)
layout = QtWidgets.QVBoxLayout(self._main)
self.static_canvas = FigureCanvas(Figure(figsize=(10, 10)))
layout.addWidget(self.static_canvas)
layout.addWidget(NavigationToolbar(self.static_canvas, self))
axes = self.static_canvas.figure.subplots(2, 1)
self.ax1 = axes[0]
self.ax2 = axes[1]
self.ax1.cla()
self.ax2.cla()
button = QtWidgets.QPushButton('Click me!')
button.clicked.connect(self.update_canvas_blit)
layout.addWidget(button)
# Fixing random state for reproducibility
np.random.seed(19680801)
# Create random data
N = 50000
x = np.random.rand(N)
y = np.random.rand(N)
self.ax1.scatter(x, y)
self.points = self.ax1.scatter([],[], s=5, color='red')
x = np.linspace(0, 1000, 100000)
self.ax2.plot(x, np.sin(x))
self.lines, = self.ax2.plot([],[], color='red')
self.static_canvas.draw()
self.background1 = self.static_canvas.copy_from_bbox(self.ax1.bbox)
self.background2 = self.static_canvas.copy_from_bbox(self.ax2.bbox)
def update_canvas_blit(self):
N = 50
x = np.random.rand(N)
y = np.random.rand(N)
self.static_canvas.restore_region(self.background1)
self.points.set_offsets(np.c_[x,y])
self.ax1.draw_artist(self.points)
self.ax1.figure.canvas.blit(self.ax1.bbox)
self.static_canvas.restore_region(self.background2)
x = np.linspace(0, np.random.randint(500,1000), 1000)
self.lines.set_data(x, np.sin(x))
self.ax2.draw_artist(self.lines)
self.ax2.figure.canvas.blit(self.ax2.bbox)
if __name__ == "__main__":
qapp = QtWidgets.QApplication(sys.argv)
app = ApplicationWindow()
app.show()
qapp.exec_()
When clicking button, expected output should be still same background with random points/lines redrawing. In a way it is happening but there are some strange artifacts that looks like somehow axes are drawn to each other. But when I try to save it to .png, it will restore to good state.
The problem is that the snapshot of the background is taken at a moment in time where the figure has not yet been shown on screen. At that point the figure is 10 by 10 inches large. Later, it is shown inside the QMainWindow and resized to fit into the widget.
Only once that has happened, it makes sense to take the background snapshot.
One option is to use a timer of 1 second and only then copy the background. This would look as follows.
import numpy as np
import sys
from matplotlib.backends.qt_compat import QtCore, QtWidgets
from matplotlib.backends.backend_qt5agg import (FigureCanvas, NavigationToolbar2QT as NavigationToolbar)
from matplotlib.figure import Figure
class ApplicationWindow(QtWidgets.QMainWindow):
def __init__(self):
super().__init__()
self._main = QtWidgets.QWidget()
self.setCentralWidget(self._main)
layout = QtWidgets.QVBoxLayout(self._main)
self.static_canvas = FigureCanvas(Figure(figsize=(10, 10)))
layout.addWidget(self.static_canvas)
layout.addWidget(NavigationToolbar(self.static_canvas, self))
axes = self.static_canvas.figure.subplots(2, 1)
self.ax1 = axes[0]
self.ax2 = axes[1]
self.ax1.cla()
self.ax2.cla()
button = QtWidgets.QPushButton('Click me!')
button.clicked.connect(self.update_canvas_blit)
layout.addWidget(button)
# Fixing random state for reproducibility
np.random.seed(19680801)
# Create random data
N = 50000
x = np.random.rand(N)
y = np.random.rand(N)
self.ax1.scatter(x, y)
self.points = self.ax1.scatter([],[], s=5, color='red')
x = np.linspace(0, 1000, 100000)
self.ax2.plot(x, np.sin(x))
self.lines, = self.ax2.plot([],[], color='red')
self.static_canvas.draw()
self._later()
def _later(self, evt=None):
self.timer = self.static_canvas.new_timer(interval=1000)
self.timer.single_shot = True
self.timer.add_callback(self.update_background)
self.timer.start()
def update_background(self, evt=None):
self.background1 = self.static_canvas.copy_from_bbox(self.ax1.bbox)
self.background2 = self.static_canvas.copy_from_bbox(self.ax2.bbox)
def update_canvas_blit(self):
N = 50
x = np.random.rand(N)
y = np.random.rand(N)
self.static_canvas.restore_region(self.background1)
self.points.set_offsets(np.c_[x,y])
self.ax1.draw_artist(self.points)
self.ax1.figure.canvas.blit(self.ax1.bbox)
self.static_canvas.restore_region(self.background2)
x = np.linspace(0, np.random.randint(500,1000), 1000)
self.lines.set_data(x, np.sin(x))
self.ax2.draw_artist(self.lines)
self.ax2.figure.canvas.blit(self.ax2.bbox)
if __name__ == "__main__":
qapp = QtWidgets.QApplication(sys.argv)
app = ApplicationWindow()
app.show()
qapp.exec_()

How to aesthetically show a generic number of axes in matplotlib?

I want to do a simple GUI that allows the user to add or remove traces from a plot for any number of traces. It looks like this:
The problems I'm having:
I don't know how to make the axes not to superpose with each other for a generic number of plots.
When I plot more than one trace, and then delete all but one, there are two axes showing for some reason. There should always be one axis per trace being shown.
Is there a way to fix these issues? You can find my code below. The only function that should be changed is update_canvas(), I believe. To try it out, just modify the list name_vars in the main with the number of variables you want. The rest of the example code is self-contained.
import numpy as np
from matplotlib.backends.qt_compat import QtWidgets
from matplotlib.backends.backend_qt5agg import FigureCanvas
from matplotlib.figure import Figure
class ApplicationWindow(QtWidgets.QMainWindow):
def __init__(self, parent=None):
super(ApplicationWindow, self).__init__(parent)
global name_vars
self.x = np.array([1,2,3,4,5])
self.y = np.random.random((5, len(name_vars)))
self.num_vars = np.size(self.y,1)
self.name_vars = name_vars
self.tags_on = [0] * self.num_vars
self.colors = ['#1F77B4','#FF7F0E','#2CA02C','#D62728','#9467BD',
'#8C564B','#E377C2','#F7F7F7','#BCBD22','#17BECF']
self._main = QtWidgets.QWidget()
self.setCentralWidget(self._main)
canvas = FigureCanvas(Figure(figsize=(10, 10)))
self.canvas_ax = canvas.figure.subplots()
self.canvas_ax.set_xlabel("Time")
self.canvas_ax_twin = []
self.list_tags = QtWidgets.QComboBox(self)
for name in self.name_vars:
self.list_tags.addItem(name)
button_add = QtWidgets.QPushButton('Add', self)
button_remove = QtWidgets.QPushButton('Remove', self)
button_add.clicked.connect(self.add_plot)
button_remove.clicked.connect(self.remove_plot)
layout = QtWidgets.QGridLayout(self._main)
layout.addWidget(canvas, 0, 0)
dropdown_layout = QtWidgets.QHBoxLayout()
dropdown_layout.addWidget(self.list_tags)
dropdown_layout.addWidget(button_add)
dropdown_layout.addWidget(button_remove)
layout.addLayout(dropdown_layout, 1, 0)
self.show()
def add_plot(self):
selected_tag = self.list_tags.currentIndex()
self.tags_on[selected_tag] = 1
self.update_canvas()
def remove_plot(self):
selected_tag = self.list_tags.currentIndex()
self.tags_on[selected_tag] = 0
self.update_canvas()
def update_canvas(self):
# Delete all traces
self.canvas_ax.clear()
[i.clear() for i in self.canvas_ax_twin]
self.canvas_ax_twin = []
num_plots = 0
for ii in range(self.num_vars):
if self.tags_on[ii] == 1:
# If it's not the first trace, create a twin axis
if num_plots != 0:
self.canvas_ax_twin.append(self.canvas_ax.twinx())
self.canvas_ax_twin[-1].plot(self.x, self.y[:,ii], self.colors[num_plots])
self.canvas_ax_twin[-1].set_ylabel(self.name_vars[ii])
self.canvas_ax_twin[-1].yaxis.label.set_color(self.colors[num_plots])
self.canvas_ax_twin[-1].tick_params(axis='y', colors=self.colors[num_plots])
num_plots += 1
# If it's the first trace, use the original axis
else:
self.canvas_ax.plot(self.x, self.y[:,ii], self.colors[num_plots])
self.canvas_ax.set_ylabel(self.name_vars[ii])
self.canvas_ax.yaxis.label.set_color(self.colors[num_plots])
self.canvas_ax.tick_params(axis='y', colors=self.colors[num_plots])
num_plots += 1
# Show the final plot
self.canvas_ax.figure.canvas.draw()
if __name__ == '__main__':
# Edit the number of elements in name_vars to try the code
name_vars = ['V1','V2','V3','V4']
app = QtWidgets.QApplication([])
ex = ApplicationWindow()
ex.show()
app.exec_()
I would suggest to separate the logic from the actual plotting. This makes it easier to follow through. This solves the second question about not removing all axes.
The question about not letting the axes superimpose may be solved by setting the position of additional twin axes to some distance from the axes, depending on how many axes you have.
ax.spines["right"].set_position(("axes", 1+(n-1)*0.1))
where n is the axes number starting from 0. The main axes (n=0) should be excluded, and the first axes will stay at position 1. Further axes are positionned in steps of 0.1.
Then it makes sense to also adjust the right margin of the main axes to give enough space for the extra spines.
import numpy as np
from matplotlib.backends.qt_compat import QtWidgets
from matplotlib.backends.backend_qt5agg import FigureCanvas
from matplotlib.figure import Figure
class ApplicationWindow(QtWidgets.QMainWindow):
def __init__(self, parent=None, name_vars=[]):
super(ApplicationWindow, self).__init__(parent)
self.x = np.array([1,2,3,4,5])
self.y = np.random.random((5, len(name_vars)))
self.num_vars = np.size(self.y,1)
self.name_vars = name_vars
self.tags_on = [0] * self.num_vars
self._main = QtWidgets.QWidget()
self.setCentralWidget(self._main)
self.figure = Figure(figsize=(10, 10))
canvas = FigureCanvas(self.figure)
self.left = self.figure.subplotpars.left
self.right = self.figure.subplotpars.right
self.canvas_ax = canvas.figure.subplots()
self.canvas_ax.set_xlabel("Time")
self.axes = [self.canvas_ax]
self.list_tags = QtWidgets.QComboBox(self)
for name in self.name_vars:
self.list_tags.addItem(name)
button_add = QtWidgets.QPushButton('Add', self)
button_remove = QtWidgets.QPushButton('Remove', self)
button_add.clicked.connect(self.add_plot)
button_remove.clicked.connect(self.remove_plot)
layout = QtWidgets.QGridLayout(self._main)
layout.addWidget(canvas, 0, 0)
dropdown_layout = QtWidgets.QHBoxLayout()
dropdown_layout.addWidget(self.list_tags)
dropdown_layout.addWidget(button_add)
dropdown_layout.addWidget(button_remove)
layout.addLayout(dropdown_layout, 1, 0)
self.show()
def add_plot(self):
selected_tag = self.list_tags.currentIndex()
self.tags_on[selected_tag] = 1
self.update_canvas()
def remove_plot(self):
selected_tag = self.list_tags.currentIndex()
self.tags_on[selected_tag] = 0
self.update_canvas()
def create_nth_axes(self, n, dataset):
if n == 0:
ax = self.canvas_ax
else:
ax = self.canvas_ax.twinx()
ax.spines["right"].set_position(("axes", 1+(n-1)*0.1))
for direction in ["left", "bottom", "top"]:
ax.spines[direction].set_visible(False)
# adjust subplotparams to make space for new axes spine
new_right = (self.right-self.left)/(1+(n-1)*0.1)+self.left
self.figure.subplots_adjust(right=new_right)
color = next(self.canvas_ax._get_lines.prop_cycler)['color']
ax.set_ylabel(self.name_vars[dataset], color=color)
ax.plot(self.x, self.y[:,dataset], color=color)
return ax
def clear_canvas(self):
# Clear main axes
self.canvas_ax.clear()
# clear and remove other axes
for ax in self.axes[1:]:
ax.clear()
ax.remove()
self.axes = [self.canvas_ax]
self.figure.subplots_adjust(right=0.9)
def update_canvas(self):
self.clear_canvas()
k = 0
for i, tag in enumerate(self.tags_on):
if tag:
ax = self.create_nth_axes(k, i)
if k > 0:
self.axes.append(ax)
k += 1
self.canvas_ax.figure.canvas.draw()
if __name__ == '__main__':
# Edit the number of elements in name_vars to try the code
name_vars = ['V1','V2','V3','V4']
app = QtWidgets.QApplication([])
ex = ApplicationWindow(name_vars=name_vars)
ex.show()
app.exec_()

Connect Qslider and MatplotlibWidget

I am a real beginner in python and try to connect a qslider to a matplotlibwidget.
That means if I change the value of the slider the graph should change. It seems that the value changes correctly, while the graph stays the same. Can anyone tell me how to connect the change of the slider with the graph? Here is my algorithm so far:
# -*- coding: utf-8 -*-
"""
Created on Tue Feb 04 16:48:12 2014
#author: Christoph
"""
from PyQt4 import QtGui, QtCore
from matplotlib.backends.backend_qt4agg import FigureCanvasQTAgg as Canvas
from matplotlib.figure import Figure
from matplotlib import rcParams
import numpy as np
import scipy.constants as const
import sys
rcParams['font.size'] = 9
class MatplotlibWidget(Canvas):
"""
MatplotlibWidget inherits PyQt4.QtGui.QWidget
and matplotlib.backend_bases.FigureCanvasBase
Options: option_name (default_value)
-------
parent (None): parent widget
title (''): figure title
xlabel (''): X-axis label
ylabel (''): Y-axis label
xlim (None): X-axis limits ([min, max])
ylim (None): Y-axis limits ([min, max])
xscale ('linear'): X-axis scale
yscale ('linear'): Y-axis scale
width (4): width in inches
height (3): height in inches
dpi (100): resolution in dpi
hold (False): if False, figure will be cleared each time plot is called
Widget attributes:
-----------------
figure: instance of matplotlib.figure.Figure
axes: figure axes
Example:
-------
self.widget = MatplotlibWidget(self, yscale='log', hold=True)
from numpy import linspace
x = linspace(-10, 10)
self.widget.axes.plot(x, x**2)
self.wdiget.axes.plot(x, x**3)
"""
def __init__(self, parent=None, title='', xlabel='', ylabel='',
xlim=None, ylim=None, xscale='linear', yscale='linear',
width=4, height=3, dpi=100, hold=False):
self.figure = Figure(figsize=(width, height), dpi=dpi)
self.axes = self.figure.add_subplot(111)
self.axes.set_title(title)
self.axes.set_xlabel(xlabel)
self.axes.set_ylabel(ylabel)
if xscale is not None:
self.axes.set_xscale(xscale)
if yscale is not None:
self.axes.set_yscale(yscale)
if xlim is not None:
self.axes.set_xlim(*xlim)
if ylim is not None:
self.axes.set_ylim(*ylim)
self.axes.hold(hold)
Canvas.__init__(self, self.figure)
self.setParent(parent)
Canvas.setSizePolicy(self, QtGui.QSizePolicy.Expanding, QtGui.QSizePolicy.Expanding)
Canvas.updateGeometry(self)
def sizeHint(self):
w, h = self.get_width_height()
return QtGui.QSize(w, h)
def minimumSizeHint(self):
return QtGui.QSize(10, 10)
class ApplicationWindow(QtGui.QMainWindow):
def __init__(self):
QtGui.QMainWindow.__init__(self)
# Graphics Window
self.mpl = MatplotlibWidget(self, title='Graph',
xlabel='x',
ylabel='y',
hold=True)
self.mpl.setGeometry(0,0,1300,800)
self.setGeometry(0, 30, 1680, 800)
# Slider Resistance
title1=QtGui.QLabel(self)
title1.setText('R')
title1.move(1400,10)
self.value1=QtGui.QLabel(self)
self.value1.setText('1')
self.value1.move(1550,40)
cb=QtGui.QSlider(QtCore.Qt.Horizontal, self)
cb.setGeometry(1400,40,100,30)
cb.setMinimum(1)
cb.setMaximum(10000)
cb.valueChanged.connect(self.Rout)
self.plot(1, self.mpl.axes)
def Rout(self, position):
self.value1.setText('%i' %position)
self.plot(position, self.mpl.axes)
def plot(self, R, axes):
x=np.linspace(0,5,1001)
B=0.035
n1=0.115
H=2.06227451e-15
n2=1.37040209e-01
gamma=0.001*const.e
C=0.13
x=np.array(x)
diodetheo = H*(np.exp((const.e*x*n2)/(const.k*300))-1)
zaehler = 1+np.exp((B-C+n1*x)*const.e/(const.k*300))
nenner = 1+np.exp((B-C-n1*x)*const.e/(const.k*300))
A=8.7476434*10**(29)*gamma
D=gamma/2
klammer2 = (const.pi/2)+np.arctan((C-n1*x)/D)
y1 = A*np.log(zaehler/nenner)*klammer2
# plt.figure()
# plt.plot(x, diodetheo, 'g')
# plt.show()
indup=[]
inddown=[]
iup=[]
idown=[]
theo = (y1+diodetheo)*(10**(-12))*(100)/4
for i, Volt in enumerate(x):
xup=np.linspace(0,Volt,i+1)
last=Volt/R-xup/R
diff=np.array(last)-np.array(theo[0:i+1])
inter=np.where(np.diff(np.sign(diff)))[0]
if inter.size==0:
inter=np.array([0])
indup.append(inter[0])
inddown.append(inter[-1])
iup.append(theo[inter[0]])
idown.append(theo[inter[-1]])
up = np.array(iup)
down = np.array(idown)
down=np.flipud(down)
ytotal=np.concatenate((up, down))
xneg=np.flipud(x)
xtotal=np.concatenate((x,xneg))
#plt.figure()
#plt.plot(xtotal, ytotal, 'g')
#plt.show()
axes.plot(xtotal, ytotal, 'r')
if __name__ == '__main__':
app = QtGui.QApplication(sys.argv)
win = ApplicationWindow()
win.show()
sys.exit(app.exec_())
Greetings
Christoph
OK I've made some changes to your code in order to make it works:
Change the function definition def plot(self, R, axes): for def plot(self, R):
Change the call self.plot(position, self.mpl.axes) on Rout accordingly to self.plot(position)
Change the final line axes.plot(xtotal, ytotal, 'r') on the previous plot function by:
self.mpl.axes.clear() #clear the previous plot
self.mpl.axes.plot(xtotal, ytotal, 'r') #replot
self.mpl.figure.canvas.draw() #redraw the canvas
Explanations:
First, you don't need to pass the axes to the plot function if it's already an attribute of self.mpl and is easy accessible. Second, when you make another plot you need to clear the previous one and also refresh the canvas.
Next all the code with modifications for easy use of copy-paste:
from PyQt4 import QtGui, QtCore
from matplotlib.backends.backend_qt4agg import FigureCanvasQTAgg as Canvas
from matplotlib.figure import Figure
from matplotlib import rcParams
import numpy as np
import scipy.constants as const
import sys
rcParams['font.size'] = 9
class MatplotlibWidget(Canvas):
"""
MatplotlibWidget inherits PyQt4.QtGui.QWidget
and matplotlib.backend_bases.FigureCanvasBase
Options: option_name (default_value)
-------
parent (None): parent widget
title (''): figure title
xlabel (''): X-axis label
ylabel (''): Y-axis label
xlim (None): X-axis limits ([min, max])
ylim (None): Y-axis limits ([min, max])
xscale ('linear'): X-axis scale
yscale ('linear'): Y-axis scale
width (4): width in inches
height (3): height in inches
dpi (100): resolution in dpi
hold (False): if False, figure will be cleared each time plot is called
Widget attributes:
-----------------
figure: instance of matplotlib.figure.Figure
axes: figure axes
Example:
-------
self.widget = MatplotlibWidget(self, yscale='log', hold=True)
from numpy import linspace
x = linspace(-10, 10)
self.widget.axes.plot(x, x**2)
self.wdiget.axes.plot(x, x**3)
"""
def __init__(self, parent=None, title='', xlabel='', ylabel='',
xlim=None, ylim=None, xscale='linear', yscale='linear',
width=4, height=3, dpi=100, hold=False):
self.figure = Figure(figsize=(width, height), dpi=dpi)
self.axes = self.figure.add_subplot(111)
self.axes.set_title(title)
self.axes.set_xlabel(xlabel)
self.axes.set_ylabel(ylabel)
if xscale is not None:
self.axes.set_xscale(xscale)
if yscale is not None:
self.axes.set_yscale(yscale)
if xlim is not None:
self.axes.set_xlim(*xlim)
if ylim is not None:
self.axes.set_ylim(*ylim)
self.axes.hold(hold)
Canvas.__init__(self, self.figure)
self.setParent(parent)
Canvas.setSizePolicy(self, QtGui.QSizePolicy.Expanding, QtGui.QSizePolicy.Expanding)
Canvas.updateGeometry(self)
def sizeHint(self):
w, h = self.get_width_height()
return QtGui.QSize(w, h)
def minimumSizeHint(self):
return QtGui.QSize(10, 10)
class ApplicationWindow(QtGui.QMainWindow):
def __init__(self):
QtGui.QMainWindow.__init__(self)
# Graphics Window
self.mpl = MatplotlibWidget(self, title='Graph',
xlabel='x',
ylabel='y',
hold=True)
self.mpl.setGeometry(0,0,1300,800)
self.setGeometry(0, 30, 1680, 800)
# Slider Resistance
title1=QtGui.QLabel(self)
title1.setText('R')
title1.move(1400,10)
self.value1=QtGui.QLabel(self)
self.value1.setText('1')
self.value1.move(1550,40)
cb=QtGui.QSlider(QtCore.Qt.Horizontal, self)
cb.setGeometry(1400,40,100,30)
cb.setMinimum(1)
cb.setMaximum(10000)
cb.valueChanged.connect(self.Rout)
self.plot(1)
def Rout(self, position):
self.value1.setText('%i' %position)
self.plot(position)
def plot(self, R):
x=np.linspace(0,5,1001)
B=0.035
n1=0.115
H=2.06227451e-15
n2=1.37040209e-01
gamma=0.001*const.e
C=0.13
x=np.array(x)
diodetheo = H*(np.exp((const.e*x*n2)/(const.k*300))-1)
zaehler = 1+np.exp((B-C+n1*x)*const.e/(const.k*300))
nenner = 1+np.exp((B-C-n1*x)*const.e/(const.k*300))
A=8.7476434*10**(29)*gamma
D=gamma/2
klammer2 = (const.pi/2)+np.arctan((C-n1*x)/D)
y1 = A*np.log(zaehler/nenner)*klammer2
# plt.figure()
# plt.plot(x, diodetheo, 'g')
# plt.show()
indup=[]
inddown=[]
iup=[]
idown=[]
theo = (y1+diodetheo)*(10**(-12))*(100)/4
for i, Volt in enumerate(x):
xup=np.linspace(0,Volt,i+1)
last=Volt/R-xup/R
diff=np.array(last)-np.array(theo[0:i+1])
inter=np.where(np.diff(np.sign(diff)))[0]
if inter.size==0:
inter=np.array([0])
indup.append(inter[0])
inddown.append(inter[-1])
iup.append(theo[inter[0]])
idown.append(theo[inter[-1]])
up = np.array(iup)
down = np.array(idown)
down=np.flipud(down)
ytotal=np.concatenate((up, down))
xneg=np.flipud(x)
xtotal=np.concatenate((x,xneg))
#plt.figure()
#plt.plot(xtotal, ytotal, 'g')
#plt.show()
self.mpl.axes.clear()
self.mpl.axes.plot(xtotal, ytotal, 'r')
self.mpl.figure.canvas.draw()
if __name__ == '__main__':
app = QtGui.QApplication(sys.argv)
win = ApplicationWindow()
win.show()
sys.exit(app.exec_())

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