> On 2 Jul 2024, at 10:59 AM, maitri ksh <maitri....@gmail.com> wrote: > > A variable 'arecomplex' which is by default set to false inside > PetscBinaryRead() overrides 'complex', true in PetscBinaryRead(file, > "complex", true) thus giving real valued output unless one manually changes > arecomplex=true inside the function.
No, you do not need to edit this function. I’m not a MATLAB expert, but I guess there is a difference between “complex", true (what you are using) and 'complex', true (what I told you to use). Thanks, Pierre > On Mon, Jul 1, 2024 at 5:40 PM Pierre Jolivet <pie...@joliv.et > <mailto:pie...@joliv.et>> wrote: >> >> >>> On 1 Jul 2024, at 4:37 PM, maitri ksh <maitri....@gmail.com >>> <mailto:maitri....@gmail.com>> wrote: >>> >>> This Message Is From an External Sender >>> This message came from outside your organization. >>> I need to export complex vectors data from PETSc and read them in MATLAB. >>> However, I am encountering some issues with the data format and >>> interpretation in MATLAB. >>> >>> code-snippet of the vector data export section: >>> // Assemble the vectors before exporting >>> ierr = VecAssemblyBegin(f); CHKERRQ(ierr); >>> ierr = VecAssemblyEnd(f); CHKERRQ(ierr); >>> >>> PetscViewer viewerf; >>> // Save the complex vectors to binary files >>> ierr = PetscViewerBinaryOpen(PETSC_COMM_WORLD, "output_f.dat", >>> FILE_MODE_WRITE, &viewerf); CHKERRQ(ierr); >>> ierr = VecView(f, viewerf); CHKERRQ(ierr); >>> ierr = PetscViewerDestroy(&viewerf); CHKERRQ(ierr); >>> >>> // Create vectors to store the magnitudes >>> Vec f_magnitude; >>> ierr = VecDuplicate(f, &f_magnitude); CHKERRQ(ierr); >>> >>> // Get local portion of the vectors >>> const PetscScalar *f_array; >>> PetscScalar *f_magnitude_array; >>> PetscInt n_local; >>> >>> ierr = VecGetLocalSize(f, &n_local); CHKERRQ(ierr); >>> ierr = VecGetArrayRead(f, &f_array); CHKERRQ(ierr); >>> ierr = VecGetArray(f_magnitude, &f_magnitude_array); CHKERRQ(ierr); >>> >>> // Compute the magnitude for each element >>> for (int i = 0; i < n_local; i++) { >>> f_magnitude_array[i] = PetscAbsScalar(f_array[i]); >>> } >>> >>> // Restore arrays >>> ierr = VecRestoreArrayRead(f, &f_array); CHKERRQ(ierr); >>> ierr = VecRestoreArray(f_magnitude, &f_magnitude_array); CHKERRQ(ierr); >>> >>> // Assemble the magnitude vectors >>> ierr = VecAssemblyBegin(f_magnitude); CHKERRQ(ierr); >>> ierr = VecAssemblyEnd(f_magnitude); CHKERRQ(ierr); >>> >>> // Save the magnitude vectors to binary files >>> PetscViewer viewerfmag; >>> ierr = PetscViewerBinaryOpen(PETSC_COMM_WORLD, "output_f_mag.dat", >>> FILE_MODE_WRITE, &viewerfmag); CHKERRQ(ierr); >>> ierr = VecView(f_magnitude, viewerfmag); CHKERRQ(ierr); >>> ierr = PetscViewerDestroy(&viewerfmag); CHKERRQ(ierr); >>> >>> In MATLAB, I am using petscBinaryRead to read the data. The complex vectors >>> are read, but only the real part is available. The magnitude vectors are >>> however read as alternating zero and non-zero elements. What went wrong? >>> How can I export the data correctly to MATLAB-accessible format? (I have >>> not configured PETSc with Matlab as I was encountering library conflict >>> issues) >> >> >> How are you reading complex-valued binary files in MATLAB? >> It is not the same as real-valued files, in particular, you must add the >> parameters 'complex', true to the PetscBinaryRead() call, type help >> PetscBinaryRead in the MATLAB console. >> >> Thanks, >> Pierre >>
