Another way to do it, using axes.get_xlim():
import matplotlib.pyplot as plt
import numpy as np
def scatter_plot_with_correlation_line(x, y, graph_filepath):
'''
http://stackoverflow.com/a/34571821/395857
x does not have to be ordered.
'''
# Create scatter plot
plt.scatter(x, y)
# Add correlation line
axes = plt.gca()
m, b = np.polyfit(x, y, 1)
X_plot = np.linspace(axes.get_xlim()[0],axes.get_xlim()[1],100)
plt.plot(X_plot, m*X_plot + b, '-')
# Save figure
plt.savefig(graph_filepath, dpi=300, format='png', bbox_inches='tight')
def main():
# Data
x = np.random.rand(100)
y = x + np.random.rand(100)*0.1
# Plot
scatter_plot_with_correlation_line(x, y, 'scatter_plot.png')
if __name__ == "__main__":
main()
#cProfile.run('main()') # if you want to do some profiling
