arecomplex = false;
tnargin = nargin;
for l=1:nargin-2
if ischar(varargin{l}) && strcmpi(varargin{l},'indices')
tnargin = min(l,tnargin-1);
indices = varargin{l+1};
end
if ischar(varargin{l}) && strcmpi(varargin{l},'precision')
tnargin = min(l,tnargin-1);
precision = varargin{l+1};
end
if ischar(varargin{l}) && strcmpi(varargin{l},'cell')
tnargin = min(l,tnargin-1);
arecell = varargin{l+1};
end
if ischar(varargin{l}) && strcmpi(varargin{l},'complex') <======== finds
any argument that is 'complex'
tnargin = min(l,tnargin-1);
arecomplex = varargin{l+1};
<======== sets arecomplex to the next argument in the list
end
end
If you are still having trouble you can use the Matlab debugger to step through
this code to see why this check is not triggered.
> On Jul 2, 2024, at 4:59 AM, maitri ksh <maitri....@gmail.com> wrote:
>
> This Message Is From an External Sender
> This message came from outside your organization.
> 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.
>
> 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
>>
>
