title: Nist Sphere format files
body: <p>In order to read NIST sphere format files, I'm trying to install NIST SPHERE software downloaded from <a href="http://www.itl.nist.gov/iad/mig//tools/" rel="nofollow">here</a>, but I encountered some errors:</p>
  
  <pre><code>make[2]: Entering directory `/home/ibtissem/tools/nist/src/bin'
  gcc  -I/home/ibtissem/tools/nist/include -L/home/ibtissem/tools/nist/lib -g -g -DNARCH_linux h_add.c  -lm -o h_add
  h_add.c:31: error: undefined reference to 'sp_verbose'
  h_add.c:31: error: undefined reference to 'sp_verbose'
  h_add.c:28: error: undefined reference to 'hs_getopt'
  h_add.c:42: error: undefined reference to 'sp_verbose'
  h_add.c:42: error: undefined reference to 'sp_get_version'
  h_add.c:44: error: undefined reference to 'hs_optind'
  h_add.c:50: error: undefined reference to 'hs_optind'
  h_add.c:53: error: undefined reference to 'hs_optind'
  h_add.c:55: error: undefined reference to 'hs_optind'
  h_add.c:71: error: undefined reference to 'sp_create_header'
  h_add.c:93: error: undefined reference to 'sp_write_header'
  h_add.c:103: error: undefined reference to 'sp_fpcopy'
  collect2: error: ld returned 1 exit status
  make[2]: *** [h_add] Error 1
  </code></pre>
  
  <p>Does someone have any idea about this error?</p>