Some commercial solvers like GuRoBi have a nifty function which can be used to write the optimization problem to a .lp file or a .mps file. For instance,GuRoBi python interface has this command,
model.write("test.lp")
I am using SCIP's c++ interface I was wondering if I can write the model I described in c++ to an lp file. Googling seems to just give me answers about reading .lp files and not writing.
You should call SCIPwriteOrigProblem.
Example:
int retcode = SCIPwriteOrigProblem(scip, "test.lp", NULL, FALSE);
assert(retcode == SCIP_OKAY);
Related
I am currently writing a C++ program that should read hex data from JPEG images. I have to compile it into one single windows executable without any external resources (like the "tessdata" directory or config files). As I am not reading any words or sentences, I don't need any dictionaries or languages.
My problem is now that I could not find a way to initialize the API without any language files. Every example uses something like this:
tesseract::TessBaseAPI api;
if (api.Init(NULL, "eng")) {
// error handling
return -1;
}
// do stuff
I also found that I can call the init function without language argument and with OEM_TESSERACT_ONLY:
if(api.Init(NULL, NULL, tesseract::OcrEngineMode::OEM_TESSERACT_ONLY)) {
// ...
}
This should disable the language/dictionary, but NULL just defaults to "eng". It seems like tesseract still wants a language file to initialize and will disable it afterwards.
This also seems to be the case for any other solutions I found so far: I always need .traineddata files to initialize the api and can disable them afterwards or using config files.
My question is now:
Is there any way to initialize the tesseract API in C++ using just the executable and no other resource files?
No. Tesseract always needs some language (default is eng) + osd (.traineddata) files. Without language data file tesseract is useless.
Your post seems that you made several wrong assumptions (e.g. about OEM_TESSERACT_ONLY), so maybe if you describe what you try to achieve with tesseract you can get better advice.
I have been trying to use the following code snippet to move a text file from one location to another (to a folder on the Desktop). However, the method of using the REN function of DOSBox or the rename function of C++ has failed.
char billfile[] = "Text.txt";
char path[67] = "ren C:\\TURBOC3\\Projects\\";
strcat(path, billfile);
strcat(path, " C:\\Users\\Admini~1\\Desktop\\Bills");
system(path);
Are there any other alternatives to this?
P.S.: This is for a school project, where Turbo C++ has to be used
Corresponding to this website for stdio.h the TurboC run-time library supports the rename function.
So even if you are obliged to use a totally outdated tool like TurboC++ it's not necessary to spawn a new process with the system function just to rename the file.
If you are using the Win32 API then consider looking into the functions CopyFile or CopyFileEx.
You can use the first in a way similar to the following:
CopyFile( szFilePath.c_str(), szCopyPath.c_str(), FALSE );
This will copy the file found at the contents of szFilePath to the contents of szCopyPath, and will return FALSE if the copy was unsuccessful. To find out more about why the function failed you can use the GetLastError() function and then look up the error codes in the Microsoft Documentation.
I currently have some code reading files which are not compressed, it uses the following approach to read a file in C++
FILE* id = fopen("myfile.dat", "r");
after obtaining id, different parts of the code access the file using fread, fseek, etc.
I would like to adapt my code so as to open a gzip version of the file, e.g. "myfile.dat.gz" without needing to change too much.
Ideally I would implement a wrapper to fopen, call it fopen2, which can read both myfile.dat and myfile.dat.gz, i.e. it should return a pointer to a FILE object, so that the remaining of the code does not need to be changed.
Any suggestions?
Thank you.
PS: it would be fine to decompress the whole file in memory, if this approach provides a solution
zlib provides analogs of fopen(), fread(), etc. called gzopen(), gzread(), etc. for reading and writing gzip files. If the file is not gzip-compressed, it will be read just as the f functions would. So you would only need to change the function names and link in zlib.
I want to experiment with some Virtual File Systems, like having 1 file in which all data is stored (1 file = virtual disk). For example I can open the virtual disk and put files into it, write data to the files, read data from file, open files and use fseek etc..
Is there any library I can use for that? License stuff etc is not important. I just want to test it on my machine because I'm borred, So I want to try this in C++/C.
Thanks in advance! :)
If the library is windows only then it's also okay, maybe I will find a linux library so I can make 2 projects?
Edit:
Thanks to BRPocock I know my question is a bit unclear. What I really want is a library which has the ability to store files, read files, and perform file operations on a VFS which the library already provides. And ofcourse mounting. So, What I would preffer is if there is a library which gives me this functions in C++:
OpenVirtualDrive(const name[]);//
CloseVirtualDrive(handle);//
fopen(const name[], mode);//open file, return handle
fclose(handle);//close handle
ftemp(); //open file as temporary file
fremove(const name[]);//delete file
fwrite(handle, array[]);//write array to file
fread(handle, array[], size = sizeof array, pack = false);//read from file
fputchar(handle, value, utf8 = true);//put char into file
fgetchar(handle, value, utf8 = true);//read char from file, move pointer
fblockwrite(handle, const buffer[], size = sizeof buffer);//write block
fblockread(handle, buffer[], size = sizeof buffer);//read block, move pointer
fseek(handle, position = 0, seek_whence: whence = seek_start);//move pointer
flength(handle);//size of file
fexist(const pattern[]);//check if file exists
fmatch(name[], const pattern[], index = 0, size = sizeof name);//search for file
This is just pseudo code :P
Linux (and many BSDs, including, I believe, MacOSX) uses the FUSE system (http://fuse.sourceforge.net/) to provide those kinds of services. You should be able to find many examples on the 'Net.
I believe the “accepted” way to do the same thing on Windows is to write it as a device-driver loadable module (.dll) … a quick Googling points at http://msdn.microsoft.com/en-us/windows/hardware/gg463062 as the starting-point, perhaps.
Our SolFS will do the job. Evaluation license will be ok for you and we offer free licenses for non-commercial public projects as well. If you want a filesystem visible from other applications, you need OS edition of SolFS, and if you are going to call its functions only from your application, then SolFS Application Edition is enough.
My programming knowlege is very limited so please take this into account when reading this. I am using Visual C++ MFC and I am looking for a basic function that would overwrite the contents of a file but keep the file the same name. I am sure this is probably fairly simple however I can't seem to find anything online. Thanks in advance for any help.
You can use CFile::Open() there is flags to specify to open an existing file without truncating it. For example if you want to create the file if it not exists, or using the alreading existing without truncating you can use CFile::modeCreate|CFile::modeNoTruncate. You can then seet to the needed position by using CFile::Seek()
It's been a while since I've done any MFC work so I'll just give you the general standard on how to do this in C/C++. This will give you a direction on how to work with MFC.
When you're opening a file, you can choose an "open flag" that tells the file system how to open it. it can be "a" for append, "r" for read, "w" for write over (trunacte), and you can add "b" if it's a binary file.
so to do that just do:
FILE *fp = fopen("my_file.whatever", "wb");
if (fp)
{
//now write to
the file... ....
fclose(fp);
}