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 >> >
