Re: Deleting charachter from a text file
- To: mathgroup at smc.vnet.net
- Subject: [mg68190] Re: Deleting charachter from a text file
- From: "Norbert Marxer" <marxer at mec.li>
- Date: Sat, 29 Jul 2006 01:00:03 -0400 (EDT)
- References: <ea722g$k1n$1@smc.vnet.net><eaa2om$nhf$1@smc.vnet.net>
- Sender: owner-wri-mathgroup at wolfram.com
Hello Giacomo
You don't need to output a correct List expression. You could use
Newline separated expressions.
You can use either WriteString ...
myStream = OpenWrite["myFile.txt"] ;
WriteString[myStream, "1"]
Do[ stepResultArray = x^i;
WriteString[myStream,
"\n", InputForm@stepResultArray] , {i, 1, 5}
] ;
Close[myStream];
... or simply Write ...
myStream = OpenWrite["myFile.txt"] ;
Write[myStream, 1]
Do[ stepResultArray = x^i;
Write[myStream, stepResultArray] , {i, 1, 5}
] ;
Close[myStream];
... and then StringSplit
StringSplit[Import["myFile.txt", "Text"], "\n"]
... to import the list of your first input expression (which is
probably not necessary anymore) and the further stepResultArray's into
Mathematica.
{1, x, x^2, x^3, x^4, x^5}
I hope this helps.
Best Regards
Norbert Marxer
www.mec.li
Giacomo Ciani wrote:
> Thanks, but this solution is not feasable for me. I'm running a
> simulation and one of the reason of writing directly on the file "step
> by step" the results is not to fill the memory, because I'm genearting
> a lot of data.
> Just for curiosity, I'm going to explain the problem in details...
> actually, what i'm doing is something like:
>
> OpenWrite[file]
> WriteString["{{zeroArray}"]
> Do[
> ...calculations...
> WriteString[file,","]
> Write[file, stepResultArray]
> ]
> WriteString["}"]
>
> taht is, I'm writing a list of "resultArrays". But as you can see, my
> list is not coled by the "}" character till the simulation has ended.
> What I would like to do is to close the list with the "}" at every
> step, and the on the next step (after "...calculations...") reopen it,
> add the new element, and close it again. This way I should be able to
> import the file in another Mathematica program at any time, even if the
> simulation is not ended...
>
> Bye, and thanks again
>
> Giacomo
>
> Jens-Peer Kuska wrote:
> > Hi,
> >
> > you must open the file, read the contents in the memory
> > and save the changed contents.
> >
> > Any editor keep the file contents in memory
> > (atleast partial) and you should do this also.
> >
> > Regards
> > Jens
> >
> > "Giacomo Ciani" <giacomo.ciani at gmail.com> schrieb
> > im Newsbeitrag news:ea4jva$sck$1 at smc.vnet.net...
> > | Hello,
> > |
> > | I'm using direct access to text files to save
> > data my program
> > | generates. So I use a syntax like:
> > |
> > | OpenWrite[file];
> > | WriteString[file,"text"];
> > | ...
> > | WriteString[file,"text2"];
> > | ...
> > | Ecc...
> > | Close[file]
> > |
> > | I would like to be able to remove some
> > characters (i.e. the last two
> > | characters) from the file before writing new
> > ones (as an example, I
> > | could need to remove the "xt" character of the
> > word "text" before
> > | writing the word "text2"). How can I accomplish
> > this? I can't find any
> > | function in the documentation to remove
> > characters from a file...
> > |
> > | Thanks
> > |
> > | Giacomo
> > |