<!-- ******************************************************** -->
<!--                                                          -->
<!--  [History]                                               -->
<!--    1st version created:  Katsuya Amako, Dec-2006         -->
<!--                                                          -->
<!-- ******************************************************** -->


<!-- ********************* QandA Section ******************** -->
<section id="qanda.RunTimeProb">
<title>
Run Time Problems
</title>

<qandaset defaultlabel="qanda">


<!-- ******* QandA Entry ******** -->
<qandaentry id="qanda.RunTimeProb.SegFltInExmp">

<question><para>
  On Linux, I get a segmentation fault as soon as I run one of the official 
  examples.
</para></question>

<answer><para>
  Check that the CLHEP library has been installed and compiled coherently 
  with the same compiler you use for installing Geant4 and for the same 
  version of Linux distribution. For example, a binary object produced with 
  Red-Hat 7.X is not fully compatible with binaries running on RH 9.X or 
  higher, due to different libc used in the two configurations.
</para></answer>

</qandaentry>


<!-- ******* QandA Entry ******** -->
<qandaentry id="qanda.RunTimeProb.ErrShareLib">

<question><para>
  I installed Geant4 libraries and built my application, when I try to run 
  it I get:
  <informalexample><programlisting>
         error in loading shared libraries:
         libCLHEP.so: cannot open shared object file:
         No such file or directory.
  </programlisting></informalexample>
</para></question>

<answer><para>
  Your installation of CLHEP includes shared libraries. You need to specify 
  the path where libCLHEP.so is installed through your environment variable 
  <literal>LD_LIBRARY_PATH</literal>. For example, in tcsh UNIX shell:
  <informalexample><programlisting>
       setenv LD_LIBRARY_PATH ${LD_LIBRARY_PATH}:$CLHEP_BASE_DIR/lib
  </programlisting></informalexample>
</para></answer>

</qandaentry>


<!-- ******* QandA Entry ******** -->
<qandaentry id="qanda.RunTimeProb.errFPE">

<question><para>
  On my system I get a Floating Point Exception (FPE) since some physics 
  processes sometimes return <literal>DBL_MAX</literal> as interaction 
  length  and this number is afterwards multiplied by a number greater 
  than 1.
</para></question>

<answer><para>
  Geant4 coding conventions and installation setup explicitly follow the 
  ANSI/IEEE-754 Standard for the initialization of floating-point 
  arithmetic hardware and portability. The Standard foresees floating-point 
  arithmetic to be nonstop and underflows to be gradual. On DEC platforms, 
  for example, the ANSI/IEEE-754 Standard compliance needs to be explicitly 
  set (since deactivated by default); in this case we use infact the option 
  "-ieee" on the DEC/cxx native C++ compiler to achieve this. You should 
  check if your compiler provides compilation options for activating Standard 
   initialization of FP arithmetic (it may be platform specific).
</para></answer>

</qandaentry>



</qandaset>
</section>
