Python matplotlib superimpose scatter plots
You simply call the scatter function twice, matplotlib will superimpose the two plots for you. You might want to specify a color, as the default for all scatter plots is blue. This is perhaps why you were only seeing one plot.
import numpy as npimport pylab as pltX = np.linspace(0,5,100)Y1 = X + 2*np.random.random(X.shape)Y2 = X**2 + np.random.random(X.shape)plt.scatter(X,Y1,color='k')plt.scatter(X,Y2,color='g')plt.show()
If you wish to continue using plot you can use the axis object returned by subplots:
import numpy as npimport pylab as pltX = np.linspace(0,5,100)Y1 = X + 2*np.random.random(X.shape)Y2 = X**2 + np.random.random(X.shape)fig, ax = plt.subplots()ax.plot(X,Y1,'o')ax.plot(X,Y2,'x')plt.show()