## How to add trendline to a scatter plot

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])