matplotlibでcorrelationの図を描く

http://stackoverflow.com/questions/8154511/drawing-a-correlation-graph-in-matplotlib

import matplotlib.pyplot as plt
import numpy as np

def plotData(inData,color):
    x,y = zip(*inData)

    xMap = assignIDs(x)
    xAsInts = np.array([xMap[i] for i in x])

    pearR = np.corrcoef(xAsInts,y)[1,0]
    # least squares from:
    # http://docs.scipy.org/doc/numpy/reference/generated/numpy.linalg.lstsq.html
    A = np.vstack([xAsInts,np.ones(len(xAsInts))]).T
    m,c = np.linalg.lstsq(A,np.array(y))[0]

    plt.scatter(xAsInts,y,label='Data '+color,color=color)
    plt.plot(xAsInts,xAsInts*m+c,color=color,
             label="Fit %6s, r = %6.2e"%(color,pearR))
    plt.xticks(xMap.values(),xMap.keys())
    plt.legend(loc=3)