how to get parts of a vector and store it as a matrix without using loops

I got a vector and I would like to transform certain parts of this vector into a new matrix without using loops. e.g. vector v=[1;2;3;4;5;6;7;8;9] and I would like to get the 4th and the 8th entry plus the two entrys before. from v=[1;2;3;4;5;6;7;8;9] to result=[2,3,4;6,7,8]

I tried to do it like this but it gets me only the first row of the result matrix

i=[4;8] result=v(i:i-2)

Any help is appreciated! Thanks

Answer 1

[Titus Edelhofer]

Hi,

the simple and readable way:

[v(i-2) v(i-1) v(i)]

and here a more complex solution:

v = (1:9)';
i = [4; 8];
v(bsxfun(@minus, i, repmat(2:-1:0, length(i), 1)))

Titus