[SCIP] how can I output my best solution using SCIPgetBestSol() to a file?

[Melvin Shih]

Dear Naga and SCIP menbers,

I am thankful for the help.
I have tried FILE* fp, and VS 2019 forced me to use fopen_s,
then SCIPprintSol() accepted the fp.
However, an Exception Unhandled occurs.
The screen picture is attached.

Actually, I need to print my problem and solution into a file to check
details, no matter using SCIP_FILE* or FILE*.
The file is also needed for further applications.
cmd screen cannot satisfy the needs.

Many thanks for your help.
Look forward to further response from you or SCIP menbers.

Sincerely,

Melvin Shih

[image: 16.png]


Naga Venkata Chaitanya Gudapati - nagavenkata.gudapati at studio.unibo.it <
nagavenkata.gudapati at studio.unibo.it> 於 2020年9月14日 週一 下午3:14寫道：

> Looks like I jumped the gun a little and just saw your full email and the
> attempt at trying to print the solution to a file. I am not sure about the
> inner workings of SCIP_FILE *  but a normal C-style FILE * seems to be
> working okay.
>
> ________________________________________
> From: Scip <scip-bounces at zib.de> on behalf of Naga Venkata Chaitanya
> Gudapati - nagavenkata.gudapati at studio.unibo.it <
> nagavenkata.gudapati at studio.unibo.it>
> Sent: Monday, September 14, 2020 7:56 AM
> To: Melvin Shih; scip at zib.de
> Subject: Re: [SCIP] how can I output my best solution using
> SCIPgetBestSol() to a file?
>
> Hi!
>
> If I understood your question correctly,
>
> You need to use
>
> SCIP_RETCODE SCIPprintSol(SCIP * scip,  SCIP_SOL * sol,  FILE * file,
> SCIP_Bool printzeros )    ;
>
> In c++, if you just want to print the solution to the console with all the
> 0 variable printed too, you can use:
>  SCIP_SOL* sol = nullptr;
>  sol = SCIPgetBestSol(scip);
>  SCIP_CALL(SCIPprintSol (scip, sol, nullptr, 1));
>
> If you want to write to a file with 0s,
> SCIP_SOL* sol = nullptr;
> sol = SCIPgetBestSol(scip);
> FILE *fp;
> fp = fopen("MYSOL.TXT", "w+");
> SCIP_CALL(SCIPprintSol (scip, sol, fp, 1));
> fclose(fp);
>
> I also have a Minimum Working Example if you need. I hope this is what you
> are looking for. I hope other SCIP members will chime in if I am wrong.
>
> Regards,
> Naga
>
>
>
> ________________________________________
> From: Scip <scip-bounces at zib.de> on behalf of Melvin Shih <
> melvinshih at gmail.com>
> Sent: Sunday, September 13, 2020 8:09 PM
> To: scip at zib.de
> Subject: [SCIP] how can I output my best solution using SCIPgetBestSol()
> to     a file?
>
> Dear SCIP members,
>
> I have tried functions of fstream and SCIP_FILE to open a file for
> SCIPgetBestSol(), and they do not work.
> Is there any example to define a file for  SCIPgetBestSol() or is there
> another way to do so using C++?
>
> Sincerely,
>
> Melvin shih
>
>
> Here are my codes:
> .............
> // fstream file;
> // file.open("Reader.txt", ios::out | ios::trunc);       //not work
>
> SCIP_FILE* schedulingfile;
> char filename[255];
> (void)SCIPsnprintf(filename, 255, "Sintex.txt");
> schedulingfile = SCIPfopen(filename, "r");
> if (schedulingfile == NULL)
> {
> SCIPerrorMessage("cannot open file <%s> for reading\n", filename);
> SCIPprintSysError(filename);
> return SCIP_NOFILE;
> }
> if (SCIPgetNSols(scip) > 0)
> {
> SCIPinfoMessage(scip, NULL, "\nSolution:\n");
> SCIP_CALL(SCIPprintSol(scip, SCIPgetBestSol(scip), schedulingfile,
> FALSE));   //SCIP_FILE is not accepted
> }
> SCIPfclose(schedulingfile);
> ..........
>
>
> _______________________________________________
> Scip mailing list
> Scip at zib.de
> https://listserv.zib.de/mailman/listinfo/scip
>
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