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How to get details from header

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kubyk
kubyk 2013-11-5
编辑： dpb 2013-11-7
I have document which contains header and data. One part of header is useless so I skipped this but in the second part are some details which I would like to save as variables.
the first part of header
ABR Group Header ==================================
Group Number: 2
Records: 16
SigGen File #1: D:\data\BioSigData\signaly\Stdpipji33.sig
SigGen File #2:
Subject ID: LEcisty
Reference #1: usporadani1
Reference #2: ABR4ch
Memo:
Start Time: Mon Apr 08 11:14
End Time: Mon Apr 08 11:16
----------------------------------------------------
the second part of header
Record Number: 24
Aqu. Duration: 19.9885 ms
Onset Delay: 0 ms
No. Points: 488
No. Averages: 300
No. Artifacts: 0
Start Time: Mon Apr 08 11:15
SigGen Index: 253
Variables:
Frequency = 7999.98 Hz
Attenuation = 0 dB
Phase = 180 DegredB
Calibration = 0 dB
data
1.18025e-005
1.04013e-005
9.32095e-006
9.15802e-006
9.79093e-006
1.04253e-005
1.02769e-005
9.14981e-006
7.38618e-006
5.5122e-006
3.99292e-006
3.07316e-006
2.70889e-006
.
.
.
I would like save inormation about duration, frequency and number of points. I don't know, how to get this details from header. Regards.

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采纳的回答

dpb
dpb 2013-11-6
Looks like a fixed format so just count lines and use the textscan ability to be called multiple times on same file...
fid=fopen(filename,'r');
dur=textscan(fid,'Aqu. Duration: %f ms','headerlines',15);
pts=textscan(fid,'No. Points: %f','headerlines',1);
frq=textscan(fid,'Frequency = %f Hz','headerlines',1);
fid=fclose(fid);
May want to cast to variable from cell.

更多回答（1 个）

kubyk
kubyk 2013-11-6
So I get details from head and the data with this code:
filename = 'usporadani11.txt';
fid = fopen (filename, 'r');
dur=textscan(fid,'Aqu. Duration: %f ms','headerlines',14);
dur=dur{1};
pts=textscan(fid,'No. Points: %f','headerlines',1);
pts=pts{1};
frq=textscan(fid,'Frequency = %f Hz','headerlines',6);
frq=frq{1};
att=textscan(fid,'Attenuation = %f dB');
att=att{1};
fs=pts/(dur/1000);
data=textscan(fid, '%f', 'headerlines', 2);
data=data{1};
fclose(fid);
But I can have several this sets in one file. It looks: header1, data1, header2, data2...header16, data16. Still the same format. Is it possible to get this ? Regards
  1 个评论
dpb
dpb 2013-11-6
编辑：dpb 2013-11-7
If it's fixed length or you can count the lines based on input in the headers, just keep on doing the same thing in a loop.
You can allocate additional cell arrays and concatenate the results or use named dynamic fields in a structure or convert the cell contents of the textscan call to an array and concatenate as storage mechanism depending on needs.
OBTW, you can save a step on the conversion--instead of
dur=textscan(fid,'Aqu. Duration: %f ms','headerlines',14);
dur=dur{1};
can write
dur=cell2mat(textscan(fid,'Aqu. Duration: %f ms','headerlines',14));
Would be nice to have the facility to return variables instead of only cells from textscan, but not to be... :(

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