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<div style="direction:ltr; font-family:Tahoma; color:#000000; font-size:10pt"><font size="2">Hi there,<br>
<br>
I am a beginner of using PETSc, and confused about the parallel distribution of matrix in PETSc. For instance, as regards the parallel dense matrices, as described in docs/developers.pdf,<br>
<br>
"The parallel dense matrices are partitioned by rows across the processors, so that each local rectangular submatrix is stored in the dense format described above."</font>
<font size="2"><br>
<br>
Does it mean each processor will have several continuous rows and all columns of the matrix? If yes, why do we need to specify "n" -- the number of local columns when calling MatCreateMPIDense?<br>
<br>
I am sorry to raise this simple question, since I have read the manual and tutorials, but I have not found a clear answer. Moreover, the reason I am asking this question is that I would like to use PETSc for matrix operations, but the elements of matrices need
to be calculate via my own code. If I know the distribution of the matrix, I could let each processor only calculate and set local values (the rows and columns possessed on the processor itself) for efficiency.<br>
<br>
My second question is if PETSc provides symmetric and anti-symmetric matrices. I have read the manual, the answer seems to be no. Am I right?<br>
<br>
Thank you in advance.<br>
<br>
Cheers<br>
<br>
Gao<br>
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