Reading single value from text file
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Hello all,
I am reading in text files of the following format and would like to extract just the Peak frequency value (6.8 below) and put it into an array. What is the easiest way to do this? Thanks, fairly new to MATLAB.
Vibration Test
9/16/2020 2:12:25 PM
Sample Rate (Hz) = 2000.00
Peak frequency (Hz) = 6.8 Resolution (Hz) = 0.2
采纳的回答
Ameer Hamza
2020-9-21
编辑：Ameer Hamza
2020-9-21
Try this
str = fileread('data.txt');
peak_freq = regexp(str, 'Peak frequency \(Hz\) =[\s\t]*(\d*\.\d*)', 'tokens');
peak_freq = str2double(peak_freq{1}{1});
data.txt file is attached.
更多回答（1 个）
Ruger28
2020-9-21
One approach, which only works if these files dont change would be to read in and point to directly where the value is.
fname = 'C:\Users\<username>\Desktop\SampleFile.txt';
FID = fopen(fname);
x = textscan(FID,'%s');
fclose(FID);
freqVal = str2double(x{1,1}{15,1});
This looks directly at the location of the freq, that is if this file format never changes. Another method would be to use fgetl to extract each line, and search for your key terms, such as:
fname = 'C:\Users\<username>\Desktop\SampleFile.txt';
FID = fopen(fname);
loopcnt = 1;
while loopcnt
temp = fgetl(FID);
if any(strfind(temp,'Peak frequency (Hz) ='))
startI = regexp(temp,'=','once');
stopI = regexp(temp,'Resolution','once');
Freq = str2double(strtrim(temp(startI+1:stopI-1)));
break
end
end
fclose(FID);
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