Constructing a patterned matrix

Hello all,

I'm a new matlab user, and I have a question on constructing a matrix that has a set pattern.

For example, say I want to make a 4x4 matrix A whose first column entries are all ones. Entries for row 1 columns 2 to 4 are 2, 3, and 4, respectively. For all columns 2 to 4, each time we go down one row, the entries are raised to the power of 2 one time.

So, the entries in column 2 would be 2, 4, 8, and 16.

Instead of entering the entries to the matrix one at a time, I'm wondering if there's a command that I can use to setup the matrix.

The actual matrix that I need to construct is actually much bigger than that, so it would take me awhile to enter the entries 1 by 1.

Thanks for any help!

Answer 1

[Oleg Komarov]

n = 4;
v = 1:n;
bsxfun(@power, v,v.')

[Jay]

Can you explain what those commands do?

Im a complete novice to matlab.

[Oleg Komarov]

They construct the matrix you asked:

1:n --> [1 2 3 4];

bsxfun(@power,v,v.') --> [1 2 3 4] to the power of [1; 2; 3; 4]. Rise v to 1 for the first row, to 2 for the second, etc...