MATLAB: copy a specific portion of an array

Question

I am trying to copy a few elements from a matrix, but not a whole row, and not a single element.

For example, in the following matrix:

a = 1 2
    3          


        

Answer 1

Elements in a matrix in MATLAB are stored in column-major order. Which means, you could even use a single index and say:

b = a(1:3);

Since the first 3 elements ARE 1,3,5. Similarly, a(6) is 2, a(7) is 4 etc. Look at the sub2ind method to understand more:

http://www.mathworks.com/help/techdoc/ref/sub2ind.html

Answer 2

You are not "removing" the second column, you are referencing the other column.

You should read some of the Matlab docs, they provide some help about the syntax for accessing portions of matrices:

http://www.mathworks.com/help/techdoc/learn_matlab/f2-12841.html#f2-428