MATLAB: How to read data from text file upto some point defined by “1”

fscanfread-data-from-file

I'm trying to read data from a number of text files (using a loop) using fscanf upto some point in the file where "1" occurs. I cannot set the "size" in fscanf(fid,'%f',size) because the "1" doesn't occur at the same place in each file. Is there a way to tell Matlab to scan only upto the "1" by something like this (it helps because no data point is equal to "1"):
while fscanf(fid,'%f',1)~=1
scan=fscanf(fid,'%f')
end

Best Answer

Assuming your file is just numbers and spaces, and that you want to stop at the first whole number equal to one (and not the 1 in 30.102 for example), no, there isn't a simpler way than using fscanf as in your example. Your while is a bit wonky though:
n = fscanf(fid, '%f', 1);
while ~isempty(n) && n~=1
   scan = [scan n];
   n = fscanf(fid, '%f', 1);
end
However, it may be more efficient / faster to just read the whole file and truncate the returned array at the first 1:
scan = fscanf(fid, '%f')
pos = find(scan == 1, 1);
scan(pos:end) = [];
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