Using textscan with txt
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Hi MATLAB Experts,
I am trying to use textscan function to read txt file, which is actually having more than 100,000 rows and 100 columns.
In order to convert data into a matrix in MATLAB, I am using for loops as follows:
fid = fopen(filename,'r');
tmp = textscan(fid,'%s','Delimiter','\n'); % there are many different data format existing (i.e. char/cell/double)
USdata = [];
for n = 2:length(tmp{1})
temp_data = regexp(tmp{1}{n},'\t','split');
USdata = [USdata; temp_data];
end
However, it takes too long since it has more than 100,000 rows. What would be the most efficient way to do it??
Thanks for any help you could provide in advance.
Jake
采纳的回答
John BG
2016-4-26
Try just reading row by row
fid=fopen('example_text.txt')
A={}
tline = fgetl(fid)
while ischar(tline)
A=[A; tline]
tline = fgetl(fid)
end
fclose(fid)
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please click on the thumbs-up vote link,
thanks in advance John
更多回答（1 个）
Walter Roberson
2016-4-25
ncol = 100;
fmt = strjoin(repmat({'%[^\t]'},1,ncol),'\t');
fid = fopen(filename,'r');
tmp = textscan(fid, fmt, 'CollectOutput', 1));
fclose(fid);
data = tmp{1};
If you know the column formats, it would be better to construct a more specific fmt. You might want to adapt some of the methods I use in http://www.mathworks.com/matlabcentral/answers/280772-how-can-i-load-target-data-on-student-alcohol-consumption#answer_219273
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