# Local numbering and Global numbering in PETSc

Hello, in PETSc, my understanding is that distributed data is a local number, that is, the number reordered in each CPU, so I think that in the above code

fespace Vh(Th, Pk);

Vh u;

u = 0:Vh. ndof - 1;

plotD(Th, u, cmm = “Local numbering”)

Where the overall number is the original number of the geometric entity defined in the grid file, and the local number is the number reordered in each CPU,

GlobalNumbering(A, u);

plotD(Th, u, cmm = “Global numbering”)

Local_numbering.edp (520 Bytes)

What is the question?

As for local number and global number, I think they are opposite. Shouldn’t the former be a global number? After grid division, it should be a global number, and the latter should not be a local number?

u[] = 0:Vh.ndof - 1;


The above can’t be global, as there is no information or numbering exchange whatsoever.

GlobalNumbering(A, u[]); // this is a global ordering as the name of the function reads

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