The source code. They are in for example src/ksp/ksp/impls/cg/cg.c Or all pretty at http://www.mcs.anl.gov/petsc/petsc-as/snapshots/petsc-current/src/ksp/ksp/impls/cg/cg.c.html#KSPCG Barry On Jan 30, 2009, at 4:10 PM, Yixun Liu wrote: > Hi, > Where can I find the details about the implementation of KSP solver > such > as CG in PETSC? > > Thanks. > > Yixun