On Thu, 28 Feb 2013, Barry Smith wrote: > > On Feb 28, 2013, at 5:33 AM, Hui Zhang <mike.hui.zhang at hotmail.com> wrote: > > > My cluster has an old version of glibc 2.3.3, which can not give usual > > principal value of square root. For example, it gives square root of -i as > > the value with negative real part. > > > > I 'grep' in the source tree of petsc and found csqrt in many places. Is > > this dangerous? Thank you! > > If you are using the default PETSc builds where it works with real numbers > then it will have no effect on. > > If you are using PETSc with complex numbers you might consider changing > the cluster software.
presumably csqrt() is c99 - so c++ std:sqrt() is perhaps ok ok? [so one could use --with-clanguage=cxx] Satish
