In this article, we will see how we can get the point object of the plot 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.). A scatter plot (aka scatter chart, scatter graph) uses dots to represent values for two different numeric variables. It is a type of plot or mathematical diagram using Cartesian coordinates to display values for typically two variables for a set of data. The position of each dot on the horizontal and vertical axis indicates values for an individual data point. Points are basically graph items which are shown as spots on scatter plot graph.
We can create a plot window and create a scatter plot graph on it with the help of commands given below.
# creating a pyqtgraph plot window plt = pg.plot() # creating a scatter plot graph of size = 10 scatter = pg.ScatterPlotItem(size=10)
In order to do this we use points method with the scatter plot graph object
Syntax : scatter.points()
Argument : It takes no argument
Return : It returns list
Below is the implementation.
# importing Qt widgets from PyQt5.QtWidgets import *
# importing system import sys
# importing numpy as np import numpy as np
# importing pyqtgraph as pg import pyqtgraph as pg
from PyQt5.QtGui import *
from PyQt5.QtCore import *
class Window(QMainWindow):
def __init__( self ):
super ().__init__()
# setting title
self .setWindowTitle( "PyQtGraph" )
# setting geometry
self .setGeometry( 100 , 100 , 600 , 500 )
# icon
icon = QIcon( "skin.png" )
# setting icon to the window
self .setWindowIcon(icon)
# calling method
self .UiComponents()
# showing all the widgets
self .show()
# method for components
def UiComponents( self ):
# creating a widget object
widget = QWidget()
# creating a label
label = QLabel( "Geeksforgeeks Scatter Plot" )
# making label do word wrap
label.setWordWrap( True )
# creating a plot window
plot = pg.plot()
# number of points
n = 300
# creating a scatter plot item
# of size = 10
# using brush to enlarge the of green color
scatter = pg.ScatterPlotItem(
size = 10 , brush = pg.mkBrush( 30 , 255 , 35 , 255 ))
# data for x-axis
x_data = [ 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 , 9 , 10 ]
# data for y-axis
y_data = [ 5 , 4 , 6 , 4 , 3 , 5 , 6 , 6 , 7 , 8 ]
# adding spots to the scatter plot
scatter.addPoints(x_data, y_data)
# add item to plot window
# adding scatter plot item to the plot window
plot.addItem(scatter)
# Creating a grid layout
layout = QGridLayout()
# minimum width value of the label
label.setMinimumWidth( 130 )
# setting this layout to the widget
widget.setLayout(layout)
# adding label in the layout
layout.addWidget(label, 1 , 0 )
# plot window goes on right side, spanning 3 rows
layout.addWidget(plot, 0 , 1 , 3 , 1 )
# setting this widget as central widget of the main window
self .setCentralWidget(widget)
# getting points object of the scatter plot
value = scatter.points()
# setting text to the value
label.setText( "Points : " + str (value))
# create pyqt5 app App = QApplication(sys.argv)
# create the instance of our Window window = Window()
# start the app sys.exit(App. exec ())
|
Output: