Can't Build Vector in While loop

Hi all, I need to search through some data and extract a specific value and then put all these values together into a vector. Here's the code I'm working with:

chtype = channels{1,1}.hdr.channeltype;
n=1;
while chtype ~= 'Edge'
  size = size(channels{n,1}.mrk, 1);
  sizeVec(n) = size;
  n = n+1;
  chtype = channels{n,1}.hdr.channeltype;
end

I get the following error:

Matrix dimensions must agree.

Error in RFSize1 (line 11) while chtype ~= 'Edge'

To me it looks like I'm just adding onto vector sizeVec with value size. I'm not sure what dimension isn't in agreement. Thank you!

Answer 1

[Geoff Hayes]

John - when comparing strings, use strcmpi or strcmp. The first would be used if you are making a case-insensitive comparison, the second if you care about case. Your code would then become

 while ~strcmp(chtype,'Edge')

or

 while ~strcmpi(chtype,'Edge')

Note that the error Matrix dimensions must agree. makes sense when comparing

 chtype ~= 'Edge'

since chtype may have a different number of elements from the four character 'Edge'.

[John Jacoby]

Thank you so much, I'm new and forgot that 'matrix' could refer to a string as well.