Can I change Matlab libraries in a program

I am trying to run a FORTRAN program (FVCOM) from Matlab. I ran into the error similar to what these folks had:

http://www.mathworks.com/matlabcentral/answers/97943-why-do-i-receive-an-error-about-gcc-version-when-executing-a-mex-file-or-an-executable-generated-by

My FORTRAN program uses a library called libnetcdf.so.7. Matlab has a built in version of this library, but it is missing a symbol that my FORTRAN program needs. So in order for me to successfully execute my program from MATLAB I need to start up Matlab using the following command from the terminal:

 LD_PRELOAD=/usr/local/lib/libnetcdf.so.7 matlab

However, before I run my FORTRAN program I want to use Matlab's netdcf abilities to create some input files needed for the program. Unfortunately, since I changed where Matlab is looking for the libnetcdf.so.7, Matlab's netcdf functions don't work because they need a symbol that is in the built in Matlab library and not in the library that is in my /user/local/lib/ directory.

Is there a way for me to set the library path after matlab has started? Ideally I would start up matlab normally (without changing the library path) and do something like:

 %%%execute matlab code using matlab's netcdf functions such as...%%%

 t=ncread(file, 'time');

 nc=netcdf.create(WindFile,'clobber');    % etc

 %%%then, in the same instance of Matlab run my Fortran program %%%

  % change my library path, but note that this doesn't work
 LD_LIBRARY_PATH=/usr/local/lib/libnetcdf.so.7  

  % run my FORTRAN program
 system(sprintf('sh run_FVCOM.sh'))

I am running Matlab R2014a on Ubunto 14.04.1

It seems like I can either startup Matlab to run my Fortran program or I can startup Matlab normally to create my netcdf files, but not both. The only work-around I can think of is to call matlab from matlab (which just seems really kludgy):

 %%%code to create my netcdf files %%%

 nc=netcdf.create(WindFile,'clobber');   % etc

 %%%code to create a new instance of matlab that calls a program to run my fortran program %%

 system(LD_PRELOAD=/usr/local/lib/libnetcdf.so.7 matlab -nodisplay -r "runfvcom")

Is there a more ellegant solution that I am not aware of?

Answer 1

[Sean de Wolski]

Are you using setenv (from within MATLAB) to set LD_LIBRARY_PATH to the environment variable? Just having it in the workspace will do nothing.

[K O'Malia]

I had tried setenv, but I was not using the correct syntax. However, trying it correctly fixed my problem and it is much more elegant than starting an entirely new instance of matlab.

 !ldd fvcom
  &nbsp &nbsp libnetcdf.so.7 => /usr/local/MATLAB/R2014a/bin/glnxa64/libnetcdf.so.7

 setenv('LD_LIBRARY_PATH', '/usr/local/lib/libnetcdf.so.7')
 !ldd fvcom
  &nbsp libnetcdf.so.7 => /usr/local/lib/libnetcdf.so.7

@Sean: Thank you. All of my searches on changing the library paths said I either had to delete/move the library (so that Matlab is forced to find it in /usr/local/lib/..) or to start matlab using LD_PRELOAD. I guess I wasn't looking in the right place, since this seems like a pretty easy and (in hindsight) obvious fix.