Yixun, > In this function I need to provide the number of rows and their global > indices and >the number of columns and their global indices. >What I want to know is if I only give these >indices regardless which porcessor ownes its indices?
Yes. User does not need to know the ownership of rows/columns. Petsc hides low-level communications to enable fast code development. When user knows the distribution of data, he is able to set values into the owned processor for better performance. Take a look at the petsc tutorial sliedes posted at http://www-unix.mcs.anl.gov/petsc/petsc-as/documentation/tutorials/index.html We have detailed introduction on this subject. >In another words, >do I need to know the indices, which this process ownes before I call this function? > You don't have to know. But if you know, you can write a better application code. Hong
