In this article we will see how we can get data of the bar graph in the PyQtGraph module. PyQtGraph is a graphics and user interface library for Python that provides functionality commonly required in designing and science applications. Its primary goals are to provide fast, interactive graphics for displaying data (plots, video, etc.) and second is to provide tools to aid in rapid application development (for example, property trees such as used in Qt Designer).A bar chart or bar graph is a chart or graph that presents categorical data with rectangular bars with heights or lengths proportional to the values that they represent. The bars can be plotted vertically or horizontally. A vertical bar chart is sometimes called a column chart. Bar graph uses two data from two list i.e for x-axis and for the height of the bars.
We can create a plot window and bar graph with the help of commands given below
# creating a pyqtgraph plot window window = pg.plot() # creating a bar graph of green color bargraph = pg.BarGraphItem(x=x, height=y1, width=0.6, brush='g')
In order to do this we use
getData
method with the bar graph objectSyntax : bargraph.getData()
Argument : It takes no argument
Return : It returns tuple
Below is the implementation
# importing QtGui to use QIcon from PyQt5.QtGui import * from PyQt5.QtCore import Qt # importing pyqtgraph as pg import pyqtgraph as pg # importing QtCore and QtGui from the pyqtgraph module from pyqtgraph.Qt import QtCore, QtGui # importing numpy as np import numpy as np import time # creating a pyqtgraph plot window window = pg.plot() # icon for plot window icon = QIcon( "logo.png" ) # setting icon to the plot window window.setWindowIcon(icon) # setting window geometry # left = 100, top = 100 # width = 600, height = 500 window.setGeometry( 100 , 100 , 600 , 500 ) # title for the plot window title = "neveropen PyQtGraph" # setting window title to plot window window.setWindowTitle(title) # create list for y-axis y1 = [ 5 , 5 , 7 , 10 , 3 , 8 , 9 , 1 , 6 , 2 ] # create horizontal list i.e x-axis x = [ 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 , 9 , 10 ] # create pyqt5graph bar graph item # with width = 0.6 # with bar colors = green bargraph = pg.BarGraphItem(x = x, height = y1, width = 0.6 , brush = 'g' ) # add item to plot window # adding bargraph item to the window window.addItem(bargraph) # getting data of the bar graph value = bargraph.getData() # printing the value print ( "Data : " + str (value)) # main method if __name__ = = '__main__' : # importing system import sys # Start Qt event loop unless running in interactive mode or using if (sys.flags.interactive ! = 1 ) or not hasattr (QtCore, 'PYQT_VERSION' ): QtGui.QApplication.instance().exec_() |
Output :
Data : ([1, 2, 3, 4, 5, 6, 7, 8, 9, 10], [5, 5, 7, 10, 3, 8, 9, 1, 6, 2])