Is there a way to indicate on a plot what different colors for each point and markers represent?-CodePudding

Is there a way I could add a box (like how I drew in the image below) to indicate what different colors for points and the different markers represent?

Or if there is any other way than adding the boxes, since I want to make it clear for the viewer what the plot exactly means.

CodePudding user response：

Yes, check out the documentation for

Slightly shorter/more compact legend:

######################### Mock Data ########################
import numpy as np
import matplotlib.pyplot as plt
time = np.arange(0,10)
y1 = np.random.randint(0, 100, 10)
y2 = np.random.randint(0, 100, 10)
y3 = np.random.randint(0, 100, 10)
df = pd.DataFrame({"time":time, "Star":y1, "Circle":y2, "Square":y3})
#############################################################

# Create custom colors based on conditions
y1Color = ["darkgreen" if x > 75 else "red" if x > 25 else "orange" for x in y1]
y2Color = ["darkgreen" if x > 75 else "red" if x > 25 else "orange" for x in y2]
y3Color = ["darkgreen" if x > 75 else "red" if x > 25 else "orange" for x in y3]

# Create custom legend based on above conditions
legend_elements = [Line2D([0], [0], marker='', color='g', label='> 75', markersize=15),
                   Line2D([0], [0], marker='', color='r', label='> 25', markersize=15),
                   Line2D([0], [0], marker='', color='orange', label='< 25', markersize=15),
                   Line2D([0], [0], marker='*', color='w', label='Star', 
                          markerfacecolor='black', markersize=15),
                   Line2D([0], [0], marker='o', color='w', label='Circle', 
                          markerfacecolor='black', markersize=15),
                   Line2D([0], [0], marker='s', color='w', label='Square',
                          markerfacecolor='black', markersize=15),]

# Plot all the points with custom colors and custom legends
plt.scatter(data=df, x="time", y="Star", marker="*", color=y1Color, s=200)
plt.scatter(data=df, x="time", y="Circle", marker="o", color=y2Color, s=200)
plt.scatter(data=df, x="time", y="Square", marker="s", color=y3Color, s=200)
plt.legend(handles=legend_elements)
plt.show()

Output

CodePudding user response：

You can use the markers provided my matplotlib and the label="" function. If you want to label them to represent numbers:

plt.plot(..., marker="", markerfacecolour="", label="")

This ensures markers have different colours and different labels!