logRegres.py 文件源码

def plotBestFit(weights):
    import matplotlib.pylab as plt
    import seaborn as sns

    dataMat,labelMat=loadDataSet()
    dataArr=array(dataMat)
    n=shape(dataArr)[0]
    xcord1=[]
    ycord1=[]
    xcord2=[]
    ycord2=[]

    for i in range(n):
        if int(labelMat[i])==1:
            xcord1.append(dataArr[i,1])
            ycord1.append(dataArr[i,2])
        else:
            xcord2.append(dataArr[i,1])
            ycord2.append(dataArr[i,2])

#    fig=plt.figure

    plt.scatter(xcord1,ycord1,s=30,c="red",marker="s",label="X1")
    plt.scatter(xcord2,ycord2,s=30,c="green",label="X2")
    x=arange(-3.0,3.0,0.1)
    y=(-float(weights[0])-float(weights[1])*x)/float(weights[2])
    plt.plot(x,y,c="purple",label="fitted line")
    plt.legend()
    plt.xlabel("X1")
    plt.ylabel("X2")
    plt.show()