How can I find and remove the rows starting with different word?
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I have a 40000 row document. The words 1 to 485 start with the letter "a". The words 486 to 1158 start with the letter "b". It starts with the letter "c" between 1158 and 4000... There are some erroneous places among these word groups. For example, there are words starting with another letter such as "b, c, d, v ..." in groups of words that should start with the letter "a" between 1 and 485. How can I find and remove the rows of these?
Thank you for your help.
Elias Gule on 29 Mar 2018
I hope this helps.
Cnew = cellfun(@char,Cnew,'uni',0); % convert the cell array contents to string
index = cellfun('isempty',(regexpi(Cnew,'^c.*'))); % find index of line not starting with C
Cnew(index) = ; % remove line not starting with C
More Answers (1)
Guillaume on 29 Mar 2018
Your english is fine and I understood what you want to do.
If the first letter of every line is belong to the character set [a-z] (and it looks like you want to ignore case), then it's very easy to solve.
However, if we have to take into account accented letters such as ğ then it's a lot more complicated because matlab has no concept of internationalisation. I have no idea where ğ is located in your alphabet but it's not going to be where matlab think it is.
If we assume US-ASCII alphabet only, the intruders can be detected easily:
firstletter = lower(cellfun(@(s) s(1), Cnew)).'; %get first letter and convert to lower case
ldiff = sign(diff(firstletter));
outoforderrows = union(strfind(ldiff, [-1 1]), strfind(ldiff, [1 -1])) + 1
But with turkish alphabet, lower may not work correctly for a start. In addition, since matlab may have the wrong idea about the order of letters, it may tell you that some lines are out of order when they are not.