RE: reading data using fgets in while loop

[financial engineer]

Thanks for the script...I rewrote mine as follows:
fname="/tmp/VIXts.csv"
fid = fopen(fname);
n=0;
while (!feof(fid))
n++
tline=strsplit(fgetl(fid),',')
datestring=sprintf('%s',tline{1});
fid(n)=str2num(tline{3});
endwhile
fclose(fid)

but when it encounters endwhile, it gives the following error:
> endwhile
error: feof: invalid stream number = -1

> Date: Mon, 12 Mar 2012 11:37:37 +0000
> From: address@hidden
> To: address@hidden
> CC: address@hidden
> Subject: Re: reading data using fgets in while loop
>
> On Sun, Mar 11, 2012 at 04:00:36PM -0700, newbie_octave wrote:
> > I have a .csv file with the following data
> >
> > 01/03/2012,H (Mar 12),26.750000,2584
> > 01/04/2012,H (Mar 12),26.280000,2330
> > 01/05/2012,H (Mar 12),26.000000,3198
> > 01/06/2012,H (Mar 12),25.500000,3045
> > 01/09/2012,H (Mar 12),25.350000,2314
> > 01/10/2012,H (Mar 12),25.050000,2685
> >
> > and I am a newbie to octave. I ran the following command to read the above
> > data into octave
> >
> > X=csvread("/tmp/hist.csv")
> >
> > but it returns the following matrix.
> >
> > 1.0000e+00 0.0000e+00 2.6750e+01 2.5840e+03
> > 1.0000e+00 0.0000e+00 2.6280e+01 2.3300e+03
> > 1.0000e+00 0.0000e+00 2.6000e+01 3.1980e+03
> > 1.0000e+00 0.0000e+00 2.5500e+01 3.0450e+03
> > 1.0000e+00 0.0000e+00 2.5350e+01 2.3140e+03
> > 1.0000e+00 0.0000e+00 2.5050e+01 2.6850e+03
> >
> >
> > Obviously, it is not reading the text correctly
> > so I am now using fgets() as follows:
> >
> > fid=fopen(fname);
> > fout="out.mat"
> > global tline;
> > global tempstr;
> > while 1
> > tline = fgets(fid);
> > sep=",";
> > tempstr=strsplit(tline, sep);
> > dt=tempstr(1);
> > cname=tempstr(2);
> > price=str2double(tempstr(3));
> > volume=str2double(tempstr(4));
> > if ~ischar(tline), break,end;
> > end
> > disp(tline);
> > fclose(fid);
> >
> > but when I run the script, it returns -1 due to disp(tline) being after the
> > end. I want to be able to compute the volume-weighted average price, and not
> > have to do it all within the script that reads the data from the file. But,
> > given that I cannot access any of the variables outside the while loop, I am
> > stuck. Ideally, I could have used csvread() or dlmread() but that is messing
> > up the string fields in my file. Can anyone please suggest how I fix this so
> > I can manipulate the variables outside the while loop that gets the data
> > from the .csv file. thanks!
> >
> >
> >
> > --
> > View this message in context: http://octave.1599824.n4.nabble.com/reading-data-using-fgets-in-while-loop-tp4464844p4464844.html
> > Sent from the Octave - General mailing list archive at Nabble.com.
>
> Hi,
> I would try while(!eof(fid)) instead of while(1).
> This would stop the while loop when the whole file is read.
>
> as an example, I've copied a part of a script that I use myself. This also does some date conversion to 'seconds since epoch'.
> To read the manual, do 'doc eof' or 'doc mktime', etc.
>
> ------------------------------------------------
> params27C.date:
> 05/12/11 18:56:37 0.001728386 16.43405 1.323835
> 05/12/11 19:26:39 0.001676934 16.41423 1.334429
> 05/12/11 19:56:40 0.001599179 16.40604 1.351362
> 05/12/11 20:54:10 0.001547091 16.35170 1.361025
> ------------------------------------------------
>
> script:
>
> pos27f=fopen('./fits2012/27C/params27C.date');
> n=0;
> while (!feof(pos27f))
> n++
> line=strsplit(fgetl(pos27f),' ')
> datestring=sprintf('%s %s',line{1},line{2});
> pos27sec(n)=mktime(strptime(datestring,'%d/%m/%y %T'));
> pos27(n)=str2num(line{4});
> endwhile
> fclose(pos27f)
>
>