设矩阵 A 为A=[24 23 9 21 6;65 74 24 11 21;34 5 98 75 21;8 42 42 53 121;43 21 45 64 21];(1) B=A(2:5,1:2:5)B = 65 24 21 34 98 21 8 42 121 43 45 21(2)A(7)=[]A =24 65 34 8 43 23 5 42 21 9 24 98 42 45 21 11 75 53 64 6 21 21 121 21(3)A+30(4)size(A);ndims(A)(5)题目有误(6)reshape(x,3,4)(7)abs(x)(8)char(x)4
L1 = 0 0 0 0 1 0 0 0 0L2 = 1 1 1 1 1 0 0 0 0L3 = 0 0 0 1 1 1 0 0 0L4 = 4 5 65
(1)B=A(1:3,:)C=A(:,1:2)D=A(2:4,3:4)E=B*CB = 23
0000 10
0000 -0
7780 0 41
0000 -45
0000 65
0000 5
0000 32
0000 5
0000 0 32
0000C = 23
0000 10
0000 41
0000 -45
0000 32
0000 5
0000 6
0000 —9
5400D = 65
0000 5
0000 0 32
0000 54
0000 3
1400E = 1
0e+003 * 0
9141 -0
2239 1
2080 2
7123 1
1330 -0
2103(2)E〈Dans = 0 1 0 0 0 1E&Dans =1 1 0 1 1 1E|Dans = 1 1 1 1 1 1~D|~Eans = 0 0 1 0 0 0find(A〉=10&A