Hello All, I am looking through the example problems given in PETSc. In the very first example, ex1 of vector section, I don't understand the following part, especially the term "PETSC_SMALL". What does this mean? Here, in the second line we already assign zero to v. What is the meaning of "if" condition then?
ierr = VecScale(x,two);CHKERRQ(ierr); ierr = VecNorm(x,NORM_2,&norm);CHKERRQ(ierr); v = norm-2.0*PetscSqrtReal((PetscReal)n); if (v > -PETSC_SMALL && v < PETSC_SMALL) v = 0.0; ierr = PetscPrintf(PETSC_COMM_WORLD,"VecScale %g\n",(double)v);CHKERRQ(ierr); All the best. Sincerely, Huq -- Fazlul Huq Graduate Research Assistant Department of Nuclear, Plasma & Radiological Engineering (NPRE) University of Illinois at Urbana-Champaign (UIUC) E-mail: huq2...@gmail.com
