Basic comparison between columns

Hello all,

Let's say I have a 10 x 10 matrix filled with numbers (10 x 10 double). When the value 999 is found (anywhere) the value in the row on the right-hand side must be 9 or it's an error. I would have thought that:

if Z(:,1:end) == 999 & Z(:,2:end)~=9 

     disp('error)
    return
  end

would work but it doesn't.

Any ideas? Thank you

[the cyclist]

When you say "right-hand side", do you mean the element just the right of each occurrence of 999 needs to be equal to 9, or that 9 needs to be in the right-most column of the matrix?

How should it be handled if 999 is in the right-most column?

Answer 1

[the cyclist]

Assuming 9 needs to be just to the right of 999 (and not handling the last column at all), I would probably do this as follows:

conditionFail = Z(:,1:end-1)==999 & not(Z(:,2:end)==9)

if any(conditionFail(:)) 
    disp('error)
    return
end

It is possible to put all the code into if statement (without needing to pre-specify the condition), like this ...

if any(any(Z(:,1:end-1)==999 & not(Z(:,2:end)==9)))
    disp('error)
    return
end

but I think that is more obfuscated.

[012786534]

You are right again!