I have to use LU decompostion to fit a simple model to some data (simulated) in C. An example of what I need to do is here:
However, I'm stuck with a more basic problem: how do I install packages in C and call them in my code?
I'm new in C and I'm used to R. But I have this assingment to do some tests about Matrix inversion, LU decomposision and the professor suggested using Lapack to easy things (thus, I don't need to code myself the LU decomposition etc.). But I don't know how to install the package and call it in my code, in order to use the functions of LAPACK.
I have a windows 7 64 bits and I'm using compiler Code Blocks 8.02
Thanks for any help.
Normally you don't "install" C libraries in that sense. Normally, in Windows you have three types of files. The header files, typically ending in .h, the dynamic library, .dll, and most likely some linker files (typically, .lib, .a or something). The linker and compiler will need to be able to find these files somewhere. Normally you set the include directory paths, and library directory paths.
E.g. Let's say you downloaded a library called foo, and you extract it to C:\foo.
In that folder, libfoo.a, foo.dll and foo.h reside. In Code::Blocks you will have to point include directory path to C:\foo and library path to C:\foo so that the linker and compiler know where to look for these files. Since you're linking against the foo library, you will also have to set -lfoo or something similiar in linker command line. This is GCC syntax, but I think Code::Blocks uses GCC compiler behind the scenes anyways.
In the C code you can just #include <foo.h> and the compiler will find it for you.
You need to install that library and it might actually supply a tool for that. Check their documentation (e.g. a file INSTALL or README in their distributed sources). If the library uses only headers you might only need to copy it's headers to some directory on your system, but their buildsystem might be able to do that for you.
Once that is done you would tell your IDE on where to look for the sources and if the library uses not just headers to link against the actual library file. See the documentation in the Code::Blocks Wiki on how this is done for some example cases and adapt for your library.
The simplest thing to do in your situation is to install Cygwin. You can use the setup.exe installer to install the GCC and the LAPACK libraries. When you want to use the LAPACK library, you will add the -llapack option to your GCC command line.
Related
Is it possible to build GMP for MSVC on Windows?
I need fully static solution (static library), without any DLL dependencies. So that my final EXE doesn't depend on any external (non-system) DLLs.
I'm alright if building GMP will need Cygwin or MSYS, as far as it can be used later in MSVC without any problems. But as far as I know at least Cygwin builds always depend on extra DLLs like cygwin1.dll which is not affordable for me, fully static-library solution is needed.
I'm aware there exists MPIR library that is more Windows friendly. But right now I need specifically GMP solution if possible.
Of course would be great if all optimizations and assembly is used when building for Windows. But if assembly is not possible then at least non-assembly (generic) variant of GMP is needed.
Of course I need 64-bit version.
If someone can post all steps needed to produce such static library for MSVC usage? Or maybe link some web-site that has such instructions?
I successfully managed to compile a working fully statically linked program with GMP using MSVC under Windows.
For that I used installation of MSYS, which is located in c:/bin/msys/ on my machine.
Then inside MSYS shell installed GMP packages mingw-w64-clang-x86_64-gmp and gmp-devel (pacman -S gmp-devel to install and pacman -Ss gmp to search).
In MSVC compiler I added include directory c:/bin/msys/clang64/include/.
Wrote an example of GMP usage program in C++, that implements Trial Division / Pollard's Rho / Pollard's P-1 factoring algorithms using long arithmetics. This program uses both mpz_...() C routines and mpz_class C++ wrapper class. For example this program is located in main.cpp.
To linker command line I added following libraries:
c:/bin/msys/clang64/lib/libgmp.a
c:/bin/msys/clang64/lib/libgmpxx.a
c:/bin/msys/mingw64/lib/gcc/x86_64-w64-mingw32/10.3.0/libgcc.a
c:/bin/msys/clang64/x86_64-w64-mingw32/lib/libmingwex.a
Also I had to add /FORCE flag (read about it here) to linker command, because libmingwex.a has some symbols overlapping with default MSVC's libraries, precisely without /FORCE I had following errors:
libucrt.lib(strnlen.obj) : error LNK2005: wcsnlen already defined in libmingwex.a(lib64_libmingwex_a-wcsnlen.o)
libucrt.lib(strnlen.obj) : error LNK2005: strnlen already defined in libmingwex.a(lib64_libmingwex_a-strnlen.o)
bin\win-msvc-m-64-release\drafts\gmp_int_msvc.exe : fatal error LNK1169: one or more multiply defined symbols found
All steps produced working (tested) final statically-linked program without any external DLL dependencies (of course except for default system DLLs of Windows).
It means MSYS's libraries .a are fully compatible with MSVC and link successfully in MSVC compilation.
Not to have /FORCE linker flag I also did extra following steps. Made a copy of c:/bin/msys/clang64/x86_64-w64-mingw32/lib/libmingwex.a library. Used c:/bin/msys/clang64/bin/objcopy.exe util, which probably was installed together with Clang. With objcopy renamed overlapping symbols:
objcopy --redefine-sym wcsnlen=msys_wcsnlen libmingwex.a
objcopy --redefine-sym strnlen=msys_strnlen libmingwex.a
which allowed me to successfully use this modified libmingwex.a library to link in MSVC without using /FORCE.
I am using the MinGW-w64 installer found here:
https://mingw-w64.org/doku.php/download/mingw-builds
Installing to a directory creates a folder called mingw32 or mingw64 that contains the compiler. I already know that the additional batch script, HTML link, and uninstall executable in the same directory can be deleted.
The mingw32/64 folder contains these folders:
bin
etc
include
lib
libexec
licenses
opt
share
i686-w64-mingw32 (mingw32) or x86_64-w64-mingw32 (mingw64)
I only wish to compile with C and nothing else. So what files can I delete in order to reduce the file count because the compiler contains files for Ruby, Fortran and other languages which as I stated, I don't need it.
Why are people still using Mingw or Mingw64 instead of TDM-GCC ? You have to rely on the default builds or build it yourself from source. Trying to install it on your own terms sucks.
TDM-GCC on the other hand, you can specify where and which components to install as you wish. You can upgrade or remove it without any worries. It's more fast, easy,modern and equivelant these days.
Now for your question, you can download and install TDM-GCC by it's installer. I don't really think you need any further instructions as a 5 year old would understand how to use it. Just select only the components required for c.
If you don't understand,I would gladly help you more if needed. ^_^
If you want a smaller GCC toolset, try MinGW Distro.
Scroll down to "How To Build Your Own Distro", download components-14.1.7z, extract it, extract binutils 2.27 and GCC 6.3.0 inside the same folder. The total size is about 270MB.
as far as i know the minimum are yours
1, bin
5. libexec
not all tools in bin you may need but generally i would hold both of those dirs
you also ned libraries and headers if you want to build abainst standard c library and windows.h, so
include
lib
is also needed (hovever part of it may contain also headers and libraries for c++ standard library) all those main 3 libs are kinda mixed there afaik so it might be a bit hard to find what comes for what
I want to my make own library and have it use the same syntax as the standard C libraries as in
#include<mylib.h>
So that it looks like #include and some of the libraries that are included with C.
Can I make the library static as opposed to linking so that I can compile it in GCC without additional arguments, as if I were using another library like stdio.h or string.h?
This seems simple enough.
Develop the library (create as many source files as you need).
Build the source files into a shared library (.so) using a tool like CMAKE (which i strongly recommend).
Copy that library to your library path (i.e. /usr/lib)
Later on, all you have to do is import your lib: (i) in the source using #include<mylib.h>; (ii) when building (also using CMAKE) or using the flag (-lmylib) in the GCC compiler: gcc -lmylib myfiles.c -o myoutput.
In addition to #include "mylib.h", you need to add -lmylib command line to the compiler (more specifically linker) when using the library. I assume that the your library archive created through ar command is named as libmylib.a.
Usually, we do not write 'manually' build instructions, but we rely on tool that generates build chains. There are quite a lot of them, the most know are probably autotools and cmake (under Linux).
I would suggest you to have a look to cmake examples and/or documentation to get your code built.
There are quite a lot of differences between static and dynamic libs, and you will also need to package somehow your lib if you really want to use it like 'standard' lib (like libxml2, openssl, etc.)
A lot to say about it, but you should first have a look to 'how to build' your lib, and then see how to make it easy to use, IMHO.
I have a c program which needs a library named libnuma to be installed. But I dont have root access in the parallel machine in which I need to run this program. So I downloaded the source code of libnuma and compiled it. I have a libnuma.a file which i assume is the library. I need to link this library with the c program that I have. This program uses autotools for generating the configuration files and the makefile. I am new to autotools. Please tell me what I have to do to link this library without being root.
Ajay.
It should be sufficient to set CPPFLAGS and LDFLAGS. First, try:
$ ./configure LDFLAGS=-L/path/to/lib CPPFLAGS=-I/path/to/include
(where libnuma.a is /path/to/lib/libnuma.a and numa.h is /path/to/include/numa.h.
That is, specify the directories.) If that does not work, check config.log to see what went wrong. If the configure script for the program you are using was built with an old version of autoconf, you may need to do:
$ LDFLAGS=-L/path/to/lib CPPFLAGS=-I/path/to/include ./configure
instead. (The second invocation will only work in Bourne shells. With csh/tcsh, you will need to set the environment variables some other way, for example with env.) You also have the option of making those settings in the environment of your shell (eg, in a .bashrc) or in a config.site file.
I am working on a multi-platform C program. The makefile has become pretty complicated because of all the different compilers, library locations, etc. on each machine. I figured Autoconf/Automake would be a good solution, though my previous experience using those tools was minimal.
My Makefile.am has the line LIBS=-lX11, but linking fails with the error "/usr/bin/ld: cannot find -lX11". I can work around this by adding "-L/usr/X11R6/lib/" to the definition of LIBS, but should I really need to do that? When I run ./configure, it says:
checking for X... libraries /usr/X11R6/lib, headers /usr/X11R6/include
So it seems like Automake should know where to find it. Is there a way I can reference its location in Makefile.am without having to hardcode it, since the X11 libs will be in a different place on each machine?
Your Makefile.am should not set LIBS. If you need to link with a library, configure.ac should include a check for the library and the configure script will set LIBS accordingly. Also, Makefile.am should not specify paths to libraries. Each system should be configured so that the precompiler can find the headers and the linker can find the libraries. If the system is not set up so that the linker can find a library, the correct solution is for the user to specify the location in LDFLAGS rather than hard coding something in Makefile.am. (eg, rather than adding -L/p/a/t/h to a Makefile, you should add LDFLAGS=-L/p/a/t/h to the invocation of configure.)