Python高斯消除

时间:2018-02-12 00:49:11

标签: python gauss

超级新编程,仍然学习如何调试。每次我运行这个程序进行高斯消除时我都会得到

  

"第16行,在GaussElim中       TMP = A [MaxRow的] [k]的   IndexError:列表索引超出范围"

我认为这意味着代码踩到了索引的极限,但我不确定如何纠正它。非常感谢任何建议,谢谢!

def GaussElim(A):
n=len(A)

for i in range(0,n):   #search for maximum in this column
    maxE1=abs(A[i][i])
    maxRow=i
    for k in range(i+1,n):
        if abs(A[k][i])>maxE1:
            maxE1=abs(A[k][i])
            maxRow=k
            # swap maximum row with current row (column by column)
    for k in range(i,n+1):
        tmp=A[maxRow][k]
        A[maxRow][k]=A[i][k]
        A[i][k]=tmp

    for k in range(i+1,n):
        c=-A[k][i]/A[i][i]
        for j in range(i,n+1):
            if i==j:
                A[k][j]=0
            else:
                A[k][j]+=c*A[i][j]
                #solve equation Ax+b for an upper triangular matrix A
x=[0 for i in range(n)]
for i in range(n-1,-1,-1):
    x[i]=A[i][n]/A[i][i]
    for k in range(i-1,-1,-1):
        A[k][n]-=A[k][i]*x[i]
return x

def main():
A=[[2,7,3,6,2],
        [3,3,4,4,6],
        [6,9,5,3,3],
        [6,9,5,3,3],
        [4,2,1,7,5]]

mysum1 = GaussElim(A)
print('a) GaussElimination Solution = {:.1f}'.format(mysum1))

1 个答案:

答案 0 :(得分:0)

在python中,列表是零索引的。如果您打印k的值,您将看到您获得的值k = 5,这可能来自您的范围(i,n + 1)(其中n = 5)。您的5x5阵列仅支持从0到4的索引。