install yael on the ubuntu 12.04

1. bits/predefs.h no such file or directory  ???

　　　　sudo apt-get install gcc-multilib

2. sudo gedit /etc/profile   PATH=$PATH:/usr/local/MATLAB/R2012a/bin 

    source /etc/profile

3.ubuntu 切换gcc 版本

     1）sudo apt-get install gcc-4.4 g++-4.4 g++-4.4-multilib gcc-4.4-multilib

     2）

root@ubuntu:~# ls /usr/bin/gcc* -l
lrwxrwxrwx 1 root root 21 Sep 18 04:42 /usr/bin/gcc -> /etc/alternatives/gcc
-rwxr-xr-x 1 root root 224544 Apr 15 22:58 /usr/bin/gcc-4.4
-rwxr-xr-x 1 root root 306200 Apr 15 19:45 /usr/bin/gcc-4.6
root@ubuntu:~#update-alternatives --install /usr/bin/gcc gcc /usr/bin/gcc-4.4 50
root@ubuntu:~#update-alternatives --install /usr/bin/g++ gcc /usr/bin/g++-4.4 50

sudo update-alternatives --install /usr/bin/gcc gcc /usr/bin/gcc-4.6 100

sudo update-alternatives --install /usr/bin/g++ g++ /usr/bin/g++-4.6 100

   3 ) sudo update-alternatives --config gcc

         sudo update-alternatives --config g++    

    to choose the gcc and g++ current version that you need

4. lsb_release -a   查看系统的版本号

5. uname -a 　　   查看系统是32位还是64位

6. /usr/bin/ld: i386:x86-64 architecture of input file `yael4matlab.a(kmeans.o)' is incompatible with i386 output

　　-m32  与 -m64之间的问题，需要根据自己platform的实际情况进行配置

7. install LAPACK and BLAS

    1) sudo apt-get install liblapack-dev

    2) download from the link http://www.netlib.org/blas/blas.tgz

        

　　$ cd $CLASSHG/codes/lapack
　　$ tar -zxf blas.tgz    # creates BLAS subdirectory
　　$ cd BLAS
　　$ gfortran -O3 -c *.f
　　$ ar cr libblas.a *.o  # creates libblas.a       
 
  reference http://faculty.washington.edu/rjl/uwamath583s11/sphinx/_build/html/lapack_install.html