OK, the mystery is solv'ed; the root cause is uiimport with it's "new and improved" flavor in wanting to use table class and then even if select columns it wants to turn text in which there are many more rows than unique values into categorical variables instead of char/cellstr and the initial code was written with string comparison operators which fail (silently, unfortunately) on categorical variables.
The workaround in short term is to convert the categorical variable to cellstr and carry on--I'll add this here to point out there really are some advantages if you will allow Matlab to have its way--consider the Details array; as you were using it, you presently are doing string comparisons to locate certain pieces of information as
Q = repmat('_1/4',[WrdVec,1]); AQ=strcmp(Details,Q);
As previously noted, you do not need the Q array to do the comparison, simply compare the array to a single string does the same job with much less memory, the length of Q in this case is over 16K. IOW,
Q = '_1/4'; AQ=strcmp(Details,Q);
is identical in result or you can even do without the temporary Q altho I can see good reason to not bury "magic strings" in the code itself so that's not a bad factoring.
OTOH, if you let Matlab go ahead and convert the input to categorical, you can then do the same thing as
Q = '_1/4'; AQ=(Details==Q);
and eliminate the comparison function itself in favor of the equality operator.
Categorical variables have many other helpful uses in categorizing functionality as well that could turn out very useful besides just logical addressing. One nice feature that could be very helpful in debugging or otherwise looking at your data is
>> summary(Deteils) Deteils 1 _0.1G 1789 _0.2G 667 _0.3G 819 _0.4G 847 _0.500 1 _1/4 812 _1/8 889 _100 50 _500 563 _65 50 _8000 5130 _Alarm 100 _GPS receive 1 _Half 566 _WOT 495 _3/8 678 _5000 47 _Complete(HSTT) 1 <undefined> 2954 >>
that produces a summary of the categories; easy to find a miscoded entry that way, maybe, if nothing else? (I just imported the file, didn't run the script so hadn't renamed the array you'll notice.)
All in all, I'd suggest revisiting the subject and consider perhaps using some of the newer features instead of beating MATLAB totally into submission.