what is the meaning of for A(1,1:8) where A is a matrix

need this solution in manipulation of matrix

Answer 1

[Azzi Abdelmalek]

read the documentation http://www.mathworks.com/help/matlab/learn_matlab/array-indexing.html

[Walter Roberson]

To summarize:

A(1,1:8)

will be a row vector composed of the first 8 elements of row 1 of A, equivalent to [A(1,1), A(1,2), A(1,3), A(1,4), A(1,5), A(1,6), A(1,7), A(1,8)]

Answer 2

[Thong Tran]

a = 1 : 4 : 8

[Walter Roberson]

The 4 is the increment between elements. See https://www.mathworks.com/help/matlab/ref/colon.html#bvg1wnp-i

Answer 3

[Tapan]

S = 1:4:9

[Walter Roberson]

S = 1:4:9

S = 1×3

1 5 9

As you can see, the first output is the same as the first entry of the 1:4:9 . You can see that for the second entry of the output, 4 has been added to the first entry of the output, and 4 is the same as the middle of the 1:4:9 clause. After that, 4 was added again to the second output, getting 9, and 9 is not greater than the third member of the 1:4:9 clause, so 9 is output. Then, 4 is added again to that output, getting 13, and 13 is greater than the third member of the 1:4:9 clause, so the 13 is not output, and the expansion of the expression stops.