- swapping a matrix

a =

     1     3     5     6     7
     2     3     2     3     2
     5     6     7     8     7

b=

     5     2     1     3     7
     6     8     2     3     1
     5     7     8     6     3

how to swap b to a.

ans=

     1     3     5     6     7
     2     3     2     3     2
     5     6     7     8     7

Answer 1

[Andrew Newell]

If I understand your latest comment, you begin by finding the unique numbers:

an = unique(a,'stable').'
bn = unique(b,'stable').'

an =

     1     3     5     6     7     2     8

bn =

     5     2     1     3     7     6     8

Now you take all the 5's in b and replace them by 1's, all the 2's by 3's, and so on, all at once (otherwise in a later step all the 1's will be changed back to 5's). You can do this by initializing a new matrix and putting all the numbers in it:

c = zeros(size(b));
for i=1:length(an)
idx = (b==bn(i));
c(idx) = an(i);
end
c

c =

     1     5     7     8     6
     2     3     5     8     7
     1     6     3     2     8

This seems to be what you're saying, although the result is completely different from the answer you provided.

Answer 2

[Andrew Newell]

I have two theories for what you mean:

b=a

just makes b equal to a. Or

z=b
b=a
a=z

exchanges the two matrices. I think you need to look at a Matlab tutorial or two.

[Anusha]

Receiver side i dont know the a value..i know only b values means.. how to make b to a

[Chandrasekhar]

do you want to assign the value of b to a? then you just have to do

a = b;

what is the receiver side variable in your question?

[Anusha]

I know only b matrix, make to my b matrix to a..

[Geoff Hayes]

Are you expecting there to be some sort of general rule or function that maps the elements of b back to the elements of a? An "inverse mapping" of some kind?

[Anusha]

yes sir

[Andrew Newell]

If you just supply a single example of a and b, there are an infinite number of rules that could map b to a. Do you have any other information?

[Anusha]

I use following comments to take a valu an=unique(a,'stable'); bn=unique(b,'stable');

Now swap an and bn in b value. this is useful to get a?

[Geoff Hayes]

Was there some sort of suggestion (or part of the problem description) that to do the swap you can use the unique values of a and b (retrieved via stable)?