title: using cython in combination with gsl
body: <p>I am using Cython and i wanted to import gnu scientific C library.</p>
  
  <pre><code>#gsl_test.pyx
  
  cdef extern from "gsl/gsl_math.h":
  double gsl_pow_int (double x, int n)
  def gibbs(double k, int t):    
  y = gsl_pow_int (k, t)
  return y
  
  #setup.py 
  
  from distutils.core import setup
  from distutils.extension import Extension
  from Cython.Distutils import build_ext
  import numpy
  
  include_gsl_dir = "/home/sulabh/include/"
  lib_gsl_dir = "/home/sulabh/lib/"
  
  
  ext = Extension("sl", sources = ["gsl_test.pyx"],include_dirs=[numpy.get_include(),include_gsl_dir],library_dirs=[lib_gsl_dir],libraries=["gsl"])
  
  setup(ext_modules=[ext],cmdclass = {'build_ext': build_ext})
  
  
  
  python setup.py build_ext --inplace
  
  which resulted into sl.o
  </code></pre>
  
  <p>I have entered into python console to import this module by writing <code>import sl</code>, but I got an error</p>
  
  <pre><code>import sl
  Traceback (most recent call last):
  File "&lt;stdin&gt;", line 1, in &lt;module&gt;
  ImportError: /home/sulabh/lib/libgsl.so.0: undefined symbol: cblas_dasum
  </code></pre>
  
  <p>here is how my package configuration looks like</p>
  
  <pre><code>prefix=/home/sulabh/gsl-1.16/..
  exec_prefix=/home/sulabh/gsl-1.16/..
  libdir=/home/sulabh/gsl-1.16/../lib
  includedir=/home/sulabh/gsl-1.16/../include
  GSL_CBLAS_LIB=-lgslcblas
  </code></pre>
  
  <p>Name: GSL
  Description: GNU Scientific Library
  Version: 1.16
  Libs: -L/home/sulabh/gsl-1.16/../lib -lgsl ${GSL_CBLAS_LIB} -lm -lm
  Cflags: -I/home/sulabh/gsl-1.16/../include</p>
  
  <p>can anybody help</p>