In this article, we will see how we can create a scatter plot graph in the PyQtGraph module which have different color spots. 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. The main concept of showing different color spots is that we will create spots in the form of a dictionary which will have the color and position property.
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 have to do the following
- Import pyqtgraph, pyqt5 and numpy modules
- Create Main window class
- Create a plot window object
- Create a scatter plot item object
- Create an empty list for storing each spot
- With the help of loops create a spot dictionary that has the keys as ‘pos’, ‘color’, ‘pen’, ‘size’ for the position, color, pen and size of the spot.
- Add these spot dictionary to the list
- Add the list to the scatter plot item as spots list
- Add this scatter plot to the plot window, and further add this plot to the grid layout with other extra widgets like the label
Below is the implementation
Python3
# importing Qt widgetsfrom PyQt5.QtWidgets import *# importing systemimport sys# importing numpy as npimport numpy as np# importing pyqtgraph as pgimport pyqtgraph as pgfrom PyQt5.QtGui import *from PyQt5.QtCore import *from collections import namedtupleclass 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() # text text = "GeeksforLazyroar Scatter Plot Graph with different color spots" # creating a label label = QLabel(text) # setting minimum width label.setMinimumWidth(130) # making label do word wrap label.setWordWrap(True) # setting configuration options pg.setConfigOptions(antialias = True) # creating a plot window plt = pg.plot() # creating scatter plot item ## Set pxMode=False to allow spots to transform with the view scatter = pg.ScatterPlotItem(pxMode = False) # creating empty list for spots spots = [] # creating loop for rows and column for i in range(10): for j in range(10): # creating spot position which get updated after each iteration # of color which also get updated spot_dic = {'pos': (1e-6 * i, 1e-6 * j), 'size': 1e-6, 'pen': {'color': 'w', 'width': 2}, 'brush': pg.intColor(i * 10 + j, 100)} # adding spot_dic in the list of spots spots.append(spot_dic) # adding spots to the scatter plot scatter.addPoints(spots) # adding scatter plot to the plot window plt.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(plt, 0, 1, 3, 1) # setting this widget as central widget of the main window self.setCentralWidget(widget)# create pyqt5 appApp = QApplication(sys.argv)# create the instance of our Windowwindow = Window()# start the appsys.exit(App.exec()) |
Output :
