Question

用rand(n,m)函数生成一个5*5 矩阵A,并且计算它的范数

Answer 1

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>> A=rand(5,5)

A =

0.9501 0.7621 0.6154 0.4057 0.0579

0.2311 0.4565 0.7919 0.9355 0.3529

0.6068 0.0185 0.9218 0.9169 0.8132

0.4860 0.8214 0.7382 0.4103 0.0099

0.8913 0.4447 0.1763 0.8936 0.1389

>> s1=abs(A)

s1 =

0.9501 0.7621 0.6154 0.4057 0.0579

0.2311 0.4565 0.7919 0.9355 0.3529

0.6068 0.0185 0.9218 0.9169 0.8132

0.4860 0.8214 0.7382 0.4103 0.0099

0.8913 0.4447 0.1763 0.8936 0.1389

>> a=A(2,1)

a =

0.2311

>> A(2,3)=5

A =

0.9501 0.7621 0.6154 0.4057 0.0579

0.2311 0.4565 5.0000 0.9355 0.3529

0.6068 0.0185 0.9218 0.9169 0.8132

0.4860 0.8214 0.7382 0.4103 0.0099

0.8913 0.4447 0.1763 0.8936 0.1389

>> B=sum(A)

B =

3.1654 2.5032 7.4517 3.5620 1.3727

>> max(B)

ans =

7.4517