python写的列主元Gauss消去法

# -*- coding: UTF-8 -*- class ClassGauss(object): def __init__(self, a, b): super(ClassGauss, self).__init__() self.a = a self.b = b self.n = len(self.b) def max(self, max_i, max_v, i, j):# get max a = self.a abs_of_a = abs(a[i][j]) if max_v < abs_of_a: max_v = abs_of_a max_i = i return max_i, max_v def swap(self, ai, j):# change line a = self.a b = self.b n = self.n for i in range(0, n): temp = a[ai][i] a[ai][i] = a[j][i] a[j][i] = temp tempb = b[ai] b[ai] = b[j] b[j] = tempb def gauss(self): n = self.n max_i = 0 # line num of max value max_v = m = self.a[0][0] for j in range(0, n-1): for i in range(j, n): max_i, max_v = self.max(max_i, max_v, i, j) if max_v == 0: raise ValueError('no unique solution') if debug: print('max_v = %f' % max_v) print('max_i = %f , j = %f' % (max_i, j)) if max_i != j: # jiaohuan ai hang he ajhang self.swap(max_i, j) if debug: print('SWAP*******') print(self.a) print(self.b) for p in range(j+1, n): l = a[p][j] / a[j][j] # print('l = %f' % (l)) b[p] -= l * b[j] for q in range(j, n): a[p][q] -= l * a[j][q] if debug: print('CAL_a******') print(self.a) print(self.b) max_v = m if debug: print("************************") print(self.a) print(self.b) self.calculate() def calculate(self): n = self.n - 1 xn = b[n] / a[n][n] print('xn = %f'% xn) if __name__ == '__main__': # example1 a = [[0.012, 0.0100, 0.1670], [1.000, 0.8334, 5.910], [3200, 1200, 4.200]] b = [0.6781, 12.10, 983.3] debug = False # example2 # a = [[2.00, -4.00, 2.00],[1.00, 2.00, 3.00],[-3.00, -2.00, 5.00]] # b = [2.00, 3.00, 1.00] g = ClassGauss(a,b) g.gauss()