eigs and ARPACK

[Thomas Treichl]

Thomas Weber schrieb:
> On Sat, Jan 03, 2009 at 08:39:54PM +0100, Thomas Treichl wrote:
>> At the moment I still have the problem that linking of liboctave.dylib 
>> fails because of undefined symbols:
>>
>>   ld: Undefined symbols:
>>   _dnaupd_
>>   _dneupd_
>>   _dsaupd_
>>   _dseupd_
>>   _znaupd_
>>   _zneupd_
>>   /usr/libexec/gcc/i686-apple-darwin8/4.0.1/libtool:
>>     internal link edit command failed
>>
>> that's why I added "$(ARPACK_LIBS)" to "LINK_DEPS" of "Makefile.in" in 
>> the directory of liboctave. I cheated, and also compiled the latest 
>> Octave sources on my virtual Debian GNU/Linux box. That system doesn't 
>> need to know anything about $(ARPACK_LIBS) for liboctave.so but just 
>> compiles fine without that information - can you help me to understand 
>> where GNU/Linux gets it's information about these functions from? 
> 
> ld checks /usr/lib (and some other paths) by default.

Sure, but does ld also check each library in these paths for function names ? 
How does ld know that eg. the function "dneupd" is part of /usr/lib/libarpack* 
and is not defined in /usr/lib/libelse.* if not "-larpack" is explicitly used 
for linking? That's where I have the problem of understanding or, as already 
mentioned, I overlook something?!

> How did you install arpack on Debian?

I installed the libarpack-dev package with "apt-get install". Thanks for help again,

   Thomas