User`s guide

Platform Limitations
2-25
Using Another BLAS
You may also use BLAS from other sources than the ones shipped with
MATLAB, provided they are in the correct format. This format is a shared
library (as opposed to a static library) that exports all the double-precision
(starting with d) and double-precision complex (starting with z) BLAS routines
from
dasum to zupmtr. On HP, IBM_RS, and WIN32, the symbols must be
exported without trailing underscores, while for ALPHA, GLNX86, SGI, and
SOL2, the symbols must be exported with trailing underscores (e.g.,
dgemm_ ).
If the shared library you provide also includes LAPACK symbols like
dgefa (or
dgefa_ ), then they will override the MATLAB default implementation, which
is based on the Fortran LAPACK from Netlib at
http://netlib.org.