In this article, we will see how we can create a scatter plot graph in the PyQtGraph module which shows text instead of symbols as 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 text as spots is that we will create a text which will act as the spots.
We can create a plot window and create 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)
Approach:
1. Import pyqtgraph, pyqt5 and numpy modules
2. Create Main window class
3. Create a plot window object
4. Create a method for creating label which return the text symbol which is named tuple
5. Create random strings using numpy
6. Create random position using numpy for plotting the strings
7. Create a scatter plot item
8. Create spots using random strings and position and add them to the scatter plot
9. Add the scatter plot graph to the plot window
10. Add plot window and extra label widget to the grid layout of main window
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() # creating a label label = QLabel("GeeksforLazyroar Scatter Plot Graph with 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() # text symbols TextSymbol = namedtuple("TextSymbol", "label symbol scale") # number of text n = 150 # method for creating label def createLabel(label, angle): # QPainterPath symbol = QPainterPath() # creating QFont object f = QFont() # setting font size f.setPointSize(10) # adding text symbol.addText(0, 0, f, label) # getting bounding rectangle br = symbol.boundingRect() # getting scale scale = min(1. / br.width(), 1. / br.height()) # getting transform object tr = QTransform() # setting scale to transform object tr.scale(scale, scale) # rotate the transform tr.rotate(angle) # translating tr.translate(-br.x() - br.width() / 2., -br.y() - br.height() / 2.) # returning text symbol return TextSymbol(label, tr.map(symbol), 0.1 / scale) # creating a random string def random_str(): return ( ''.join([chr(np.random.randint(ord('A'), ord('z'))) for i in range(np.random.randint(1, 5))]), np.random.randint(0, 360)) # plotting the scatter plot scatter = pg.ScatterPlotItem(size=10, pen=pg.mkPen('w'), pxMode=True) # getting random position pos = np.random.normal(size=(2, n), scale=1e-5) # creating spots spots = [{'pos': pos[:, i], 'data': 1, 'brush': pg.intColor(i, n), 'symbol': i % 5, 'size': 5 + i / 10.} for i in range(n)] # adding spots to the scatter plot scatter.addPoints(spots) # spots spots = [{'pos': pos[:, i], 'data': 1, 'brush': pg.intColor(i, n), 'symbol': label[1], 'size': label[2] * (5 + i / 10.)} for (i, label) in [(i, createLabel(*random_str())) for i in range(n)]] # adding points 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 :
