Getting unnecessary stop words from text in matlab? - matlab

Question

stopwords_cellstring={'a','s', 'about', 'above', 'above', 'across', 'after', ...
'afterwards', 'again', 'against', 'all', 'almost', 'alone', 'along', ...
'already', 'also','although','always','am','among', 'amongst', 'amoungst', ...
'amount', 'an', 'and', 'another', 'any','anyhow','anyone','anything','anyway', ...
'anywhere', 'are', 'around', 'as', 'at', 'back','be','became', 'because','become',...
'becomes', 'becoming', 'been', 'before', 'beforehand', 'behind', 'being', 'below',...
'beside', 'besides', 'between', 'beyond', 'bill','all','When', 'both', 'bottom','but', 'by',...
'call', 'can', 'cannot', 'cant', 'co', 'con', 'could', 'couldnt', 'cry', 'de',...
'describe', 'detail', 'do', 'done', 'down', 'due', 'during', 'each', 'eg', 'eight',...
'either', 'eleven','else', 'elsewhere', 'empty', 'enough', 'etc', 'even', 'ever', ...
'every', 'everyone', 'everything', 'everywhere', 'except', 'few', 'fifteen', 'fify',...
'fill', 'find', 'fire', 'first', 'five', 'for', 'former', 'formerly', 'forty', 'found',...
'four', 'from', 'front', 'full', 'further', 'get', 'give', 'go', 'had', 'has', 'hasnt',...
'have', 'he', 'hence', 'her', 'here', 'hereafter', 'hereby', 'herein', 'hereupon', ...
'hers', 'herself', 'him', 'himself', 'his', 'how', 'however', 'hundred', 'ie', 'if',...
'in', 'inc', 'indeed', 'interest', 'into', 'is', 'it', 'its', 'itself', 'keep', 'last',...
'latter', 'latterly', 'least', 'less', 'ltd', 'made', 'many', 'may', 'me', 'meanwhile',...
'might', 'mill', 'mine', 'more', 'moreover', 'most', 'mostly', 'move', 'much', 'must',...
'my', 'myself', 'name', 'namely', 'neither', 'never', 'nevertheless', 'next', 'nine',...
'no', 'nobody', 'none', 'noone', 'nor', 'not', 'nothing', 'now', 'nowhere', 'of', 'off',...
'often', 'on', 'once', 'one', 'only', 'onto', 'or', 'other', 'others', 'otherwise',...
'our', 'ours', 'ourselves', 'out', 'over', 'own','part', 'per', 'perhaps', 'please',...
'put', 'rather', 're', 'same', 'see', 'seem', 'seemed', 'seeming', 'seems', 'serious',...
'several', 'she', 'should', 'show', 'side', 'since', 'sincere', 'six', 'sixty', 'so',...
'some', 'somehow', 'someone', 'something', 'sometime', 'sometimes', 'somewhere', ...
'still', 'such', 'system', 'take', 'ten', 'than', 'that', 'the', 'their', 'them',...
'themselves', 'then', 'thence', 'there', 'thereafter', 'thereby', 'therefore', ...
'therein', 'thereupon', 'these', 'they', 'thickv', 'thin', 'third', 'this', 'those',...
'though', 'three', 'through', 'throughout', 'thru', 'thus', 'to', 'together', 'too',...
'top', 'toward', 'towards', 'twelve', 'twenty', 'two', 'un', 'under', 'until', 'up',...
'upon', 'us', 'very', 'via', 'was', 'we','all', 'well', 'were','uses','way','went', 'what', 'whatever', 'when',...
'whence', 'whenever', 'where', 'whereafter', 'whereas', 'whereby', 'wherein',...
'whereupon', 'wherever', 'whether', 'which', 'while', 'whither', 'who', 'whoever',...
'whole','When', 'whom', 'whose','saw', 'why', 'will', 'with', 'within', 'without', 'would', 'yet',...
'you', 'your', 'yours', 'yourself', 'yourselves', 'the'};
above are the stop words that i am using to process a text file and removing them but there are some words which are not still eliminated listed as follows:
[3] 'The'
[6] 'â'
[5] 's'
can anyone help me how to eliminate these words the code i'm using is as follows
str1 = F
split1 = regexp(str1,'\s','Split');
out_str1 = strjoin(split1(~ismember(split1,stopwords_cellstring)),' ')
C = regexp(out_str1, '<s>|\w*|</s>', 'match');

Answer 1

Just concentrating on word filtering and if willing to be case insensitive, using ~ismember will not work. Here is a solution to filter stopwords while being not case sensitive:
str1 = F
split1 = regexp(str1,'\s','Split');
%%%%
logic = arrayfun(#(word)any(strcmpi(word, stopwords_cellstring)), split1);
out_str1 = strjoin(split1(~logic), ' ');
%%%%
C = regexp(out_str1, '<s>|\w*|</s>', 'match');
How it works:
I have replaced ismember test with arrayfun. For each word in split1, the arrayfun checks if this word match any of the words in stopwords_cellstring using strcmpi (case insensitive).
NB1: For s it is not part of your stop list.
NB2: For â, I don't know if there's a quick solution to convert it to a (i.e without accentuation) ... easy solution would be to add it to your list unless it is included in more complex word like âmer for instance ... in this last case I would advice you to prefilter str1 with str1 = strrep(str1, 'â', 'a').