PyQtGraph – Different Colored Spots on Scatter Plot Graph

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 

1. Import pyqtgraph, pyqt5 and numpy modules
2. Create Main window class
3. Create a plot window object
4. Create a scatter plot item object
5. Create an empty list for storing each spot
6. 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.
7. Add these spot dictionary to the list
8. Add the list to the scatter plot item as spots list
9. 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 

Output :