use library (gcc) in matlab and error with compile of mex - matlab

I am using Mac OSX (yosemite V 10.10.1) and running MATLAB 2014a on it.
I wanted to use SPAM library (sparse modeling software by J. Mairal) on MATLAB and for that I have to install XCode6.1 (that has gcc). First I type in command window mex -setup and result is shown below:
mex -setup
MEX configured to use 'Xcode with Clang' for C language compilation.
Warning: The MATLAB C and Fortran API has changed to support MATLAB
variables with more than 2^32-1 elements. In the near future
you will be required to update your code to utilize the
new API. You can find more information about this at:
http://www.mathworks.com/help/matlab/matlab_external/upgrading-mex-files-to-use-64-bit-api.html.
To choose a different language, select one from the following:
mex -setup C++
mex -setup FORTRAN
So after that I run the compile.m file in SPAM library and suddenly I saw an error that was:
add_flag =
-mmacosx-version-min=10.6
Warning: Directory already exists.
> In compile at 144
compilation of: -I./linalg/ -I./decomp/ -I./prox/ -I./dictLearn/ dictLearn/mex/mexArchetypalAnalysis.cpp
Building with 'Xcode Clang++'.
clang: warning: argument unused during compilation: '-fopenmp'
Error using mex
ld: warning: directory not found for option '-L/usr/lib/gcc/x86_64-linux-gnu/4.8/'
ld: library not found for -lgomp
clang: error: linker command failed with exit code 1 (use -v to see invocation)
Error in compile (line 439)
mex(args{:});
I don't understand what to do. please help me!

It appears that the actual error is occurring at the point of linking with precompiled libraries. The 2 issues are as follows:
The compile code apparently included in the compile.m file looks like it is intended to compile with gcc (it is trying to include files installed by GCC, possibly even linux-specific ones, are you sure that it's an OSX-compatible toolbox?), and yet the error strongly suggests that you are in fact using clang to compile it - you will either need to change the compiler (easy) or rewrite compile.m (not so easy).
One of the libraries that the code needs to have installed in order to be properly linked hasn't been found. On OSX I think this file should be called libgomp.dylib (any mac afficionados want to confirm this?). If you have it on your computer, then it's not in a directory that clang is looking in. You can confirm the library is installed by running find / | grep libgomp.dylib from the terminal - if it is there, you can add it into the compiler argument in compile.m using the -I /DIRECTORY_HOLDING_LIBRARY syntax.
It is entirely possible that fixing 1. will also remediate 2. - I have never tried using SPAM

Related

Matlab mex can not build but gcc can

I'm new to Matlab and was trying to build a C file. The code gets compiled fine with gcc (4.8.4 in 64-bit Ubuntu). But when I try to build with mex, it shows following error:
error: exponent has no digits
I'm not sure what I'm doing wrong. The error is in this file. Complete error log is here.
When I compile the code using gcc, there are no errors. I do not provide any special arguments to gcc. To my knowledge, mex is using gcc so I do not understand why mex is failing to build the code.
I've little knowledge of C programming and any help is highly appreciated!
Edit:
To clarify more, I've got the source in two files:
File 1 has the C code with a main function, and uses functions from this
file (which mex can not build).
File 2 has the C code of the S-Function which call's File 1's main function. File 2 has an include statement to include File 1.
When I said I can build using gcc, I just built File 1 with this command: gcc file1.c -o file1. I think not building File 2 with gcc has no impact here in my question, as only File 1 uses those functions from the file which mex can not build.
I used this command from Matlab mex file2.c to build and got the error.
For C code, you probably need to enable GNU extensions for C99 (-std=gnu99). As described in my previous post on enabling C99, to pass this to mex:
mex -v -largeArrayDims CFLAGS="\$CFLAGS -std=gnu99" mexSouce.c
The reason the default does not work is because mex likes to choose the ANSI standard, which is often not the newest.

installing libsvm on Mac (OSX 10.9.2)

I have tried to install the libsvm package with
mex -setup
(since "make" resulted in an error). This was followed by one choice for a compiler, so I chose "1".
Afterwards I typed in "make" got the following error though:
xcrun: error: SDK "macosx10.7" cannot be located
clang: warning: no such sysroot directory: '-mmacosx-version-min=10.7'
libsvmread.c:1:10: fatal error: 'stdio.h' file not found
#include <stdio.h>
^
1 error generated.
mex: compile of ' "libsvmread.c"' failed.
If make.m fails, please check README about detailed instructions.
What can I do?
I think the following answer from the matlab support might be helpful (http://www.mathworks.com/matlabcentral/answers/103904-can-i-use-xcode-5-as-my-c-or-c-compiler-in-matlab-8-1-r2013a-or-matlab-8-2-r2013b):
The Mac OS X 10.7 SDK, available in Xcode 4.1 through 4.6, is used by
MEX and related capabilities. This SDK is no longer available in Xcode
5, resulting in errors similar to the following when compiling:
xcodebuild: error: SDK "macosx10.7" cannot be located.
xcrun: error: unable to find utility "clang", not a developer tool or
in PATH
The simplest solution is to avoid updating Xcode to version 5 if you
are using R2013a or R2013b. If you need Xcode 5, or you have already
irreversibly upgraded to it, you can update MEX to use the 10.8 SDK:
In the MATLAB Command Window, execute the following commands:
cd(matlabroot)
cd bin
edit mexopts.sh
Save a backup copy of this file somewhere in case you make a mistake and you need to revert your changes.
Scroll down to the Mac (“maci64”) section of this file, beginning around line 120.
Replace all instances of 10.7 with 10.8; there are four of these in all (a fifth may be found in comments only)
Save the file, then execute the following command in the MATLAB Command Window:
mex -setup
Please note that this workaround links MEX files with a different SDK
than with which MATLAB was tested. Although there are no known
compatibility issues, support may be limited.

MATLAB can't see my C compiler to mex svmlib

I have 64-bit Mac, OS X 10.8.5, and I have xcode installed. I can also verify gcc works from the command line. When I type mex -setup I get
The options files available for mex are:
1: /Applications/MATLAB_R2013a.app/bin/mexopts.sh :
Template Options file for building MEX-files
0: Exit with no changes
This is unhelpful. And when I type make, with all of the relevant libsvm files in my folder of choice, I get
make
xcodebuild: error: SDK "macosx10.7" cannot be located.
xcrun: error: unable to find utility "clang", not a developer tool or in PATH
mex: compile of ' "libsvmread.c"' failed.
If make.m fails, please check README about detailed instructions.
Is anyone able to help me with this?
The quickest thing is to edit the mexopts.sh file directly, using your favorite text editor (you may need to do this with "Administrator Privileges"). The file:
/Applications/MATLAB_R2013a.app/bin/mexopts.sh
defines a bunch of paths and flags for invoking the C/C++ compiler on your system. It tends not to keep up with revisions to the MacOS.
On my system, I had to make the following changes:
lines 258-260
CC='gcc'
SDKROOT='/Developer/SDKs/MacOSX10.6.sdk'
MACOSX_DEPLOYMENT_TARGET='10.6'
line 273
CXX=g++
There will be many references to "CC=" in the file; you're looking for the ones that follow the line
maci64)
But the correct values for your system depend on which gcc/g++ you have and where they are installed. As you can see, I have the MacOS 10.6 Developer tools installed under /Develop. You will need an install of the Developer tools (XCode) - see
How to use/install gcc on Mac OS X 10.8 / Xcode 4.4
In more recent versions of the XCode tools, the path might look more like:
/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.9.sdk
But compiling MEX code with more recent versions of XCode might cause other problems - I had issues with char16_t, see:
MEX compile error: unknown type name 'char16_t'

make error: invalid command line option

I'm trying to make http://iridia.ulb.ac.be/~manuel/hypervolume (version 2.0) on windows using the instructions they've given in their README which is to install MINGW and run "make mex", however I keep getting this error:
$ make mex
mex -D VARIANT=4 Hypervolume_MEX.c hv.c
mex.exe: Invalid command-line option
mex.exe: Data: unknown option
make: *** [mex] Error 1
instructions given:
Guillaume Jacquenot contributed a MEX interface for MATLAB
(Hypervolume_MEX.c). Use make mex to compile it.
Any help would be appreciated thank you
Within matlab change directories to the location of the hypervolume code, then run
mex -DVARIANT=4 Hypervolume_MEX.c hv.c avl.c
at the matlab command prompt. If your c compiler is set up correctly within matlab this should generate an executable named Hypervolume_MEX.xxx (dll in my case).
edit
I used the matlab compiler (Lcc C 2.4) on Matlab 7. No luck with Visual Studio 6 or Watcom 10.6 compilers (although I did not attempt to debug).

Executing cuda program through Eclipse is giving error

I am using eclipse to execute a cuda program. I have downloaded a CUDA PLUGIN for
eclipse. When I execute sample cuda program given by plugin its fine but when I try
to execute any other program I am getting error undefined reference to main...
make
Building target: Add_cuda
Invoking: NVCC Linker
nvcc -L/export/trainee3/dinesh/cuda5.0/lib64 -o "Add_cuda" ./mycuda.o -lcudart
/usr/lib/gcc/x86_64-redhat-linux/4.1.2/../../../../lib64/crt1.o: In function `_start':
(.text+0x20): undefined reference to `main'
collect2: ld returned 1 exit status
I found in stackoverflow that some times we get this problem because of system startup file
I used flag -nostartfiles but it is not working in my case..
I have included lib64 and include path in c++ build.
So any suggestion to over come this problem....
We've been over this already.
Use nsight eclipse edition instead.
If you have cuda 5.0 or 5.5 installed, just type nsight in a terminal session.
If you really want to use that Eclipse CUDA plugin (which is no longer supported, I don't believe), then start with the C++ sample project, which you agree now and back then would work. Then modify the source code in that project. Don't create your own project.
Install CUDA 5. It comes with Nsight Eclipse version. Very Elegant to use. NV Visual profiler is integrated with Nsight. Syntax highlighting and debug mode are very easy to use.