title: Link against openblas; do I need still Lapack?
body: <p>I do compile Ipopt with openblas using the linkage: <code>./configure --with-blas-incdir="-L/home/moritz/build/CoinIpopt_test/ThirdParty/openblas/include/" --with-blas-lib="-L/home/moritz/build/CoinIpopt_test/ThirdParty/openblas/lib/ -libopenblas_sandybridgep-r0.2.14.a"</code></p>
  
  <p>If I do not define any specific LAPACK library, Ipopt automatically uses the LAPACK from netlib. Does openplas comes with its own optimized LAPACK implementation ?</p>
  
  <p>If I use <code>--with-lapack-incdir="-L/home/moritz/build/CoinIpopt_test/ThirdParty/openblas/include/" --with-lapack-lib="-L/home/moritz/build/CoinIpopt_test/ThirdParty/openblas/lib/"</code></p>
  
  <p>make fails because some Lapack routines could not be resolved e.g <code>undefined reference to</code>dpotrs_<code>
  At least there is the file</code>lapacke.h<code>in the</code>include<code>folder but there are not LAPACK libraries in the</code>lib` folder.</p>
  
  <p>I found this <a href="https://github.com/xianyi/OpenBLAS/issues/203" rel="nofollow">issue</a> on GitHub stating:</p>
  
  <blockquote>
    <p>OK, I think I figured it out...
    You can make OpenBLAS build without including LAPACK in it, by >specifying NO_LAPACK=1 on the make command line. By default, it >includes a full LAPACK lib (with some parts optimized).</p>
  </blockquote>
  
  <p>But if this is the case where are the libs ?</p>
  
  <p>Should I compile LAPACK against openblas ?</p>
  
  <p>I would highly appreciate it, if someone could shed some light on this issue.</p>