MATLAB: How can extract specific numbers from a string??

extract specific numbers from a stringmatrixnumstring

I have the string c={ 4 of 5 stars, 5 of 5 stars, 5 of 5 stars, 3 of 5 stars, 3 of 5 stars, 4 of 5 stars}. How can extract to a matrix the bold numbers ????

thank you!!!

Best Answer

You could use a regular expression. Assuming all the numbers you want to extract are integer:

str = 'c={ 4 of 5 stars, 5 of 5 stars, 5 of 5 stars, 3 of 5 stars, 3 of 5 stars, 4 of 5 stars}';
starcount = str2double(regexp(str, '\d+(?= of)', 'match'))

The regular expression matches any sequence of digit immediately followed by ' of'.

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Your post is not very clear, not help with the fact that your example does not use valid matlab syntax. Possibly, that's what you want:

ratings = {'Value,Rooms,Cleanliness,Service', '2 of 5 stars,2 of 5 stars,4 of 5 stars,2 of 5 stars'; ...
           'Value,Location,Sleep Quality,Rooms,Cleanliness,Service', '5 of 5 stars,5 of 5 stars,5 of 5 stars,5 of 5 stars,5 of 5 stars,5 of 5 stars'; ...
           'Location,Rooms,Cleanliness,Service', '4 of 5 stars,1 of 5 stars,3 of 5 stars,4 of 5 stars'}
%The above is not a very useful way to store data, so split it:
ratinglabels = cellfun(@(r) strsplit(r, ','), ratings(:, 1), 'UniformOutput', false);
ratingscores = cellfun(@(r) str2double(regexp(r, '\d+(?= of)', 'match')), ratings(:, 2), 'UniformOutput', false);  %extract score
%get unique labels, and mapping between original array and label column:
[labels, ~, destinationcolumn] = unique([ratinglabels{:}]);   
%get row destination for each score:
destinationrow = repelem(1:size(ratings, 1), cellfun(@numel, ratingscores))';
%create output matrix and fill with score. Default value if score is missing is NaN:
scores = nan(size(ratings, 1), numel(labels));
scores(sub2ind(size(scores), destinationrow, destinationcolumn)) = [ratingscores{:}];
%pretty display:
scores = array2table(scores, 'VariableNames', matlab.lang.makeValidName(labels))
%export to excel:
writetable(scores, 'someexcelfile.xlsx');

Best Answer

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