reading header line from text file

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Rami
Rami 2012-11-12
回答： Gabriel Felix 2020-5-24
Hi,
I have text file with 2 header lines and data (7 columns). I can read the data using textscan, but not able to read header file (using fgets). Please see the code below:
fid = fopen(files(1).name, 'rt');
C = textscan(fid, '%f %f %f %f %f %f %f' ,'HeaderLines',2,'Delimiter',',');
tline = fgets(fid);
fclose(fid);
It gave tline = -1.
Any help regarding the problem, will be really appreciated. Thanks, Rami
  1 个评论
Rami
Rami 2012-11-12
Hi,
I able to resolve the problem with writing fgets first and then textscan:
fid = fopen(files(1).name, 'rt');
tline = fgets(fid);disp(tline)
C = textscan(fid, '%f %f %f %f %f %f %f ' ,'HeaderLines',2,'Delimiter',',');
fclose(fid);
But now I run to another problem, how can I read the particular text from header line. For example, from header line below, I want to read number:
[Number, time(16215.00), x, y, z]
Thanks, Rami

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采纳的回答

José-Luis
José-Luis 2012-11-12
It means the position indicator is not at the beginning of the file after it exits textscan:
You can either rewind:
fid = fopen(files(1).name, 'rt');
C = textscan(fid, '%f %f %f %f %f %f %f' ,'HeaderLines',2,'Delimiter',',');
frewind(fid);
tline = fgets(fid);
fclose(fid);
Or read it first:
fid = fopen(files(1).name, 'rt');
line1 = fgets(fid);
line2 = fgets(fid);
C = textscan(fid, '%f %f %f %f %f %f %f' ,'Delimiter',',');
tline = fgets(fid);
fclose(fid);
  5 个评论
显示 3更早的评论
Dr. Seis
Dr. Seis 2012-11-12
编辑：Dr. Seis 2012-11-12
If you always have the same "somethings" then you may be able to do something like this:
headerline = '[something,something(546231122.23),x,y,z]';
number = sscanf(headerline,'[something,something(%f),x,y,z]');
Rami
Rami 2012-11-12
Thanks Elige,
That was an elegant way to get the number.
Rami

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更多回答（1 个）

Gabriel Felix
Gabriel Felix 2020-5-24
I had to use \n at the end of each line. Without it I couldn't make textscan() work properly, even thoug the "HeaderLines" was configured according to the text file lines. This was the only solution I found after struggling with the code for an intire day.
This was the text:
!
!
! alfa (graus) = 5.0
!
! Id. x/s z/s alfai cl c*cl/cmed cdi cmc/4
! (graus)
1 .246 .050 -1.209 .255 .332 .00538 .0170
2 .292 .150 -1.098 .259 .319 .00496 .0545
3 .339 .250 -.925 .254 .297 .00410 .0944
4 .385 .350 -.741 .243 .268 .00315 .1341
5 .432 .450 -.561 .227 .235 .00223 .1714
6 .479 .550 -.393 .206 .199 .00141 .2034
7 .525 .650 -.238 .181 .163 .00075 .2266
8 .572 .750 -.101 .152 .126 .00027 .2362
9 .619 .850 .014 .116 .089 -.00003 .2236
10 .659 .938 .103 .074 .052 -.00013 .1693
!
! CL asa = .208
! CDi asa = .00258
! e (%) = 88.9
! CMc/4 asa = .1339
My code:
%! alfa (graus) = 5.0
P = textscan(fid,'! alfa (graus) = %f','Delimiter',' ','MultipleDelimsAsOne',true,'headerLines',2,'CollectOutput',1);
alpha(1) = P{1};
%! CL asa = .208
P = textscan(fid,'! CL asa = %f\n','Delimiter',' ','MultipleDelimsAsOne',true,'CollectOutput',1,'headerLines',4+n);
CL(1) = P{1};
%! CDi asa = .00258
P = textscan(fid,'! CDi asa = %f\n','Delimiter',' ','MultipleDelimsAsOne',true,'CollectOutput',1,'headerlines',0);
CDi(1) = P{1};
%! CMc/4 asa = .1339
P = textscan(fid,'! CMc/4 asa = %f','Delimiter',' ','MultipleDelimsAsOne',true,'CollectOutput',1,'HeaderLines',2);
Cmc4(1) = P{1};

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