This thread suggests that I was at least not wrong in assuming that trailing 0s should be printed by printf (although I did not trace the code down to printf)
https://stackoverflow.com/questions/277772/avoid-trailing-zeroes-in-printf Maybe Sanjay's machines printf cuts off trailing 0s. On Wed, May 15, 2019 at 10:06 AM Smith, Barry F. <bsm...@mcs.anl.gov> wrote: > > The 10-20% in seven digits are presumably printed accurately; it is > presumably simply the case that the rest of the digits would be zero and > hence are not printed. > > > On May 15, 2019, at 8:59 AM, Mark Adams via petsc-users < > petsc-users@mcs.anl.gov> wrote: > > > > You are seeing half precision (like 7 digits) in 10-20% of the entries > and full in the rest. > > > > Someone will probably chime in who knows about this but I can see where > a serial matrix is printed in ASCII Matlab in MatView_SeqAIJ_ASCII in > src/mat/impls/aij/seq/aij.c. > > > > I think this line is operative and is should clearly work: > > > > ierr = PetscViewerASCIIPrintf(viewer,"%D %D > %18.16e\n",i+1,a->j[j]+1,(double)a->a[j]);CHKERRQ(ierr); > > > > Could you run in serial (this code could very well be used for MPI Mats > also) with Matlab/ASCII to verify that you have this problem. And you could > modify this print statement and remake PETSc, if that's easy, to verify > that this code is operative. > > > > I think %18.16e should print 16 digits even if they are 0s ... > > > > > > On Tue, May 14, 2019 at 8:34 PM Sanjay Govindjee <s...@berkeley.edu> > wrote: > > I'm seeing half precision on at least 10 to 20% of the entries :( > > Knowing I should see full precision, I will dig deeper. > > > > -sanjay > > On 5/14/19 5:22 PM, Mark Adams wrote: > >> I would hope you get full precision. How many digits are you seeing? > >> > >> On Tue, May 14, 2019 at 7:15 PM Sanjay Govindjee via petsc-users < > petsc-users@mcs.anl.gov> wrote: > >> I am using the following bit of code to debug a matrix. What is the > >> expected precision of the numbers that I will find in my ASCII file? > >> As far as I can tell it is not the full double precision that I was > >> expecting. > >> > >> call PetscViewerASCIIOpen(PETSC_COMM_WORLD, > >> tangview,K_view, ierr) > >> call PetscViewerSetFormat(K_view, > >> PETSC_VIEWER_ASCII_MATLAB, ierr) > >> call MatView (Kmat, K_view, ierr) > >> > >> -sanjay > >> > > > >
