# Is this a way to represent column vectors.......

• Mar 2nd 2013, 05:10 PM
ak786
Is this a way to represent column vectors.......
Hi,
I came across a representation of matrix i donot clearly understand. Is D[. , t] reprentation of a row of column vector? If not, then can anybody tell me what the dot (.) represents.

Thanks
• Mar 2nd 2013, 10:32 PM
chiro
Re: Is this a way to represent column vectors.......
Hey ak786.

This operation takes two matrices and augments them column-wise. To use an example from Octave:

>> >> A = [0,1,2;3,4,5;6,7,8]
A =

0 1 2
3 4 5
6 7 8

>> X = [1;2;3]
X =

1
2
3

>> B = [A, X]
B =

0 1 2 1
3 4 5 2
6 7 8 3

Note the requirement with the number of rows for each matrix.
• Mar 3rd 2013, 12:56 AM
ak786
Re: Is this a way to represent column vectors.......
thanks for the reply, but do u mean that '.' represents augmenting two matrices column-wise??
• Mar 3rd 2013, 01:02 AM
chiro
Re: Is this a way to represent column vectors.......
I think the dot just refers to a matrix of some sort.