PyQtGraph - Getting Cursor of Line in Line Graph

In this article, we will see how we can get a custom cursor of the line, of the line 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 line chart or line plot or line graph or curve chart is a type of chart that displays information as a series of data points called 'markers' connected by straight line segments. It is a basic type of chart common in many fields. The line graph is created with the help of plot class in PyQtGraph. The cursor is an indicator used to show the current position for user interaction on a computer monitor or other display device that will respond to input from a text input or pointing device. The mouse cursor is also called a pointer, owing to its resemblance in usage to a pointing stick. It can be set with the help of setCursor method.

We can create a plot window and create lines on it with the help of commands given below.

# creating a pyqtgraph plot window
plt = pg.plot()

# plotting line in green color
# with dot symbol as x, not a mandatory field
line = plt.plot(x, y, pen='g', symbol='x', symbolPen='g',
 symbolBrush=0.2, name='green')

In order to do this we use cursor method with the line object
Syntax : line.cursor()
Argument : It takes no argument
Return : It returns QCursor object 

Below is the implementation.

Output: