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

[Ambros Gleixner]

Dear Melvin,

I am afraid this is too unspecific for us to help from the SCIP side.

Best,
Ambros


Am 14.09.20 um 09:36 schrieb 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
> 
> 16.png
> 
> 
> Naga Venkata Chaitanya Gudapati - nagavenkata.gudapati at studio.unibo.it 
> <mailto:nagavenkata.gudapati at studio.unibo.it> 
> <nagavenkata.gudapati at studio.unibo.it 
> <mailto: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 <mailto:scip-bounces at zib.de>> on
>     behalf of Naga Venkata Chaitanya Gudapati -
>     nagavenkata.gudapati at studio.unibo.it
>     <mailto:nagavenkata.gudapati at studio.unibo.it>
>     <nagavenkata.gudapati at studio.unibo.it
>     <mailto:nagavenkata.gudapati at studio.unibo.it>>
>     Sent: Monday, September 14, 2020 7:56 AM
>     To: Melvin Shih; scip at zib.de <mailto: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 <mailto:scip-bounces at zib.de>> on
>     behalf of Melvin Shih <melvinshih at gmail.com
>     <mailto:melvinshih at gmail.com>>
>     Sent: Sunday, September 13, 2020 8:09 PM
>     To: scip at zib.de <mailto: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);
>     ..........
> 
> 
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> 
> 
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-- 
Ambros Gleixner, Research Group Mathematical Optimization Methods at 
Zuse Institute Berlin, http://www.zib.de/gleixner