combining matricies with common values

i am trying to create a matrix by combining two matricies however, i want to combine them by maching elements from both matricies such as

a=[1 2;
   1 4;
   5 8]

b=[4 4;
   8 9;
   2 9]

combined=[4 1;
          8 5;
          2 1]

i know that this should be simple but i have just started learning matlab and i wasnt able to figure it out

[Stephen23]

@ma sd: please explain the rules that you used to "combine" those matrices.

[ma sd]

i was using the second column form a matched with the first column from b

Answer 1

[the cyclist]

I'm not certain this is what you want, but this is my best guess:

[tf,idx] = ismember(b(:,1),a(:,2))
complete = [a(idx,2) a(idx,1)];

It seems like you are almost trying to use the fewest words possible to describe your question. Instead, you should try to give a complete, detailed description of what you are trying to do, so that we don't have to guess.

[ma sd]

i apologize for that what i was trying to explain is hat i have two matricies that i want to merge by matching the second column from a with the first column from b. the resultant i want is a matrix with two columns, the first being the matched value and the second is the first column from a.

[the cyclist]

FYI, there are a couple other ways to do what you wanted, after finding the correct sorting. For example

complete = [b(:,1) a(idx,1)];

or

complete = fliplr(a(idx,:));

Since you are new at MATLAB, it is good to learn a few different ways of manipulating arrays.