pythonnumpymatplotlibscatter-plottrendline

How to add trendline to a scatter plot

How could I add a trendline to a dot graph drawn using matplotlib.scatter?

Solution

  • as explained here

    With help from numpy one can calculate for example a linear fitting.

    # plot the data itself
pylab.plot(x,y,'o')

# calc the trendline
z = numpy.polyfit(x, y, 1)
p = numpy.poly1d(z)
pylab.plot(x,p(x),"r--")
# the line equation:
print "y=%.6fx+(%.6f)"%(z[0],z[1])