Hi,
I am trying to use the lapack library linked to a fortran 90 program. During the compilation I have severals errors in the lapack library functions. The typical message is:
"
/usr/lib/liblapack.a(dgesdd.o)(.text+0x8b2): In function `dgesdd_':
: undefined reference to `dgemm_'
"

It looks like the lapack library, installed by rpm, is not linked to something.
Has anybody a solution?
Thanks in advance,

Martino

You need to link to the BLAS (basic linear algebra subroutines). LAPACK depends on them for almost everything. DGEMM, for example, does a general matrix-matrix multiply in 64-bit precision. You didn't provide enough information for me to give you the exact fix. As a first stab, try adding "-lblas" to your compile line at the appropriate place (or possibly just "/usr/lib/libblas.a" at the end).

Andy

Actually I did linked to blas.
In my makefile I had
"
#######################
### Program Libraries #
#######################

LIBS = /usr/lib/libblas.a \
/usr/lib/liblapack.a
"
But now I put the library directely in the LDFLAG:
"
-L/usr/lib/ -lblas -llapack
"
and I have a different message error:
"
[martino@weinberg mcdf2003]$ make
Linking mdfgme.exe ...
/usr/lib//libblas.so: undefined reference to `e_wsfe'
/usr/lib//liblapack.so: undefined reference to `etime_'
/usr/lib//libblas.so: undefined reference to `do_fio'
/usr/lib//libblas.so: undefined reference to `s_wsfe'
make: *** [mdfgme.exe] Error 1
"
Did I miss others links or there is a problem in the libraries?
Thanks,

Martino

It looks like the libraries were built with a different compiler than the one you are using. You didn't say which one you are using or where these libraries came from. Unsatified externals with these sorts of names are always low-level Fortran system library problems, almost always caused by using different compilers or different versions of the same compiler. You can always build the BLAS library yourself using the same compiler and options which you are currently using on your Fortran source code. Get the libraries from NETLIB.ORG. They also have some already compiled library archives built with various compiling systems. These are to be preferred, since they are highly optimized. Same goes for LAPACK, by the way.

Andy