#coding: utf-8
"""
coding with python.
"""
import numpy
import matplotlib.pyplot as plt
import math
import pandas

excel = pandas.read_excel('datasetCh2_2019.xlsx',index_col=None,header=None)
exfile = excel[0].values.tolist()
x = numpy.arange(1,201)
y = exfile
xp=numpy.arange(1, 200, 0.1)
for i in range(10):
    k = i+6
    J = 0
    yp = numpy.polyval(numpy.polyfit(x,y,k),xp)
    array = numpy.polyval(numpy.polyfit(x,y,k),x)-y
    for i2 in range(len(array)):
        J += math.pow(math.ceil(array[i2]),2)
    plt.plot(xp,yp)
    plt.plot(x,y,'ro')
    plt.show()
    print("k =  "+str(k)+" ,J = "+str(J))
equation2 = numpy.polyfit(x,y,15)
xp2 = numpy.arange(1,900,1)
yp2 = numpy.polyval(equation2,xp2)
xq = [135.5, 255,  420.8, 820]
yq = numpy.polyval(equation2,xq)
plt.plot(xp2,yp2)
plt.plot(xq,yq,'ro')
plt.show()
print(yq)