RE: reading data using fgets in while loop

[financial engineer]

> Date: Mon, 12 Mar 2012 11:14:44 -0700
> From: address@hidden
> To: address@hidden
> Subject: RE: reading data using fgets in while loop
>
>
> newbie_octave wrote
> >
> >> Date: Mon, 12 Mar 2012 10:17:32 -0700
> >> From: pr.nienhuis@
> >> To: help-octave@
> >> Subject: Re: reading data using fgets in while loop
> >>
> >>
> >> 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!
> >> >
> >> > I also get the following error in using strsplit, and I don't
> >> understand
> >> > what mistake I am making as I am following the usage guidelines. I
> >> tried
> >> > split, but I am advised to use strsplit.
> >> > octave-3.2.4:110> strsplit(tline,sep)
> >> > error: Invalid call to strsplit. Correct usage is:
> >> >
> >> > -- Function File: [S] = strsplit (P, SEP, STRIP_EMPTY)
> >> >
> >> >
> >> > Additional help for built-in functions and operators is
> >> > available in the on-line version of the manual. Use the command
> >> > `doc <topic>' to search the manual index.
> >> >
> >> > Help and information about Octave is also available on the WWW
> >> > at http://www.octave.org and via the help@
> >> > mailing list.
> >> >
> >>
> >> There are a few more text reading functions that may help out.
> >> E.g., textread:
> >> (applied to your data in a file txt.csv)
> >>
> >> octave-3.6.1.exe:2> [a, b, c, d] = textread ('tst.csv', "%s %s %f %d",
> >> "delimiter", ",")
> >> a =
> >> {
> >> [1,1] = 01/03/2012
> >> [2,1] = 01/04/2012
> >> [3,1] = 01/05/2012
> >> [4,1] = 01/06/2012
> >> [5,1] = 01/09/2012
> >> [6,1] = 01/10/2012
> >> }
> >> b =
> >> {
> >> [1,1] = H (Mar 12)
> >> [2,1] = H (Mar 12)
> >> [3,1] = H (Mar 12)
> >> [4,1] = H (Mar 12)
> >> [5,1] = H (Mar 12)
> >> [6,1] = H (Mar 12)
> >> }
> >> c =
> >>
> >> 26.750
> >> 26.280
> >> 26.000
> >> 25.500
> >> 25.350
> >> 25.050
> >>
> >> d =
> >>
> >> 2584
> >> 2330
> >> 3198
> >> 3045
> >> 2314
> >> 2685
> >>
> >> With some postprocessing (e.g., datenum (a, "dd/mm/yyyy") ) you can get
> >> any
> >> output you want.
> >>
> >> Philip
> >>
> >>
> >> --
> >> View this message in context:
> >> http://octave.1599824.n4.nabble.com/reading-data-using-fgets-in-while-loop-tp4464844p4466694.html
> >> Sent from the Octave - General mailing list archive at Nabble.com.
> >> _______________________________________________
> >> Help-octave mailing list
> >> Help-octave@
> >> https://mailman.cae.wisc.edu/listinfo/help-octave
> >
> > thanks Philip,
> > ...I realize that I don't have textread.m in my io folder. can you tell me
> > where can I download it.
> > Bobby
> >
>
> What Octave version on what operating system are we talking about?
>
> I showed how to use textread() with Octave v.3.6.1; in 3.6.0 textread was
> significantly improved.
>
> If your Octave version is not too old (should be >= 3.4.0) you might
> download textread.m + the required companion file strread.m here:
> http://hg.savannah.gnu.org/hgweb/octave/file/05635e4c605a/scripts/io
> and replace the ones on your hard disk in
> ./share/octave/<version>/m/io
> (You'll have to search a bit where this exactly is, I don't know my way
> around on your PC)
>
> If you run an older Octave version (3.2.4 on Windows?) you're strongly
> advised to upgrade a.s.a.p.
>
> Philip
>
> --
> View this message in context: http://octave.1599824.n4.nabble.com/reading-data-using-fgets-in-while-loop-tp4464844p4466883.html
> Sent from the Octave - General mailing list archive at Nabble.com.
> _______________________________________________
> Help-octave mailing list
> address@hidden
> https://mailman.cae.wisc.edu/listinfo/help-octave

hi Philip,
yes indeed, my version is older...I am running
octave-3.2.4:1>
this is the standard package in the applications in ubuntu v.10, and that is what I installed.
thanks for that link...it seems like I am missing a few .m running the older version.
thanks,
Bobby