<html><head><style type='text/css'>p { margin: 0; }</style></head><body><div style='font-family: Times New Roman; font-size: 12pt; color: #000000'>So, first you decide if the global mesh is periodic. Let's say it is periodic in i direction.<br><blockquote style="border-left:2px solid rgb(16, 16, 255);margin-left:5px;padding-left:5px;"><div id="DWT4862" style="font-family: Times New Roman; font-size: 12pt; color: #000000"><br>When you SCDInterface::compute_partition, you pass gdims [3]-gdims[0] = N+1, where N is the number of cells, even if it is periodic in i.<br><br></div></blockquote>That was wrong, it is gdims [3]-gdims[0] = N<br><br>Iulian<br><blockquote style="border-left: 2px solid rgb(16, 16, 255); margin-left: 5px; padding-left: 5px;"><div style="font-family: Times New Roman; font-size: 12pt; color: rgb(0, 0, 0);">If (ldims[3]-ldims[0] == gdims[3]-gdims[0]) it means that your partition was not broken in i direction, so when you create the box, you have to do periodic in i, so it will create only N nodes in i direction.<br><br>It is a bad case (small number of processors, or number of data in j direction is very large compared to i). In "most" of the cases, you should have a break in both directions, then your periodicity will be broken.<br><br>But you have to account for these "worse case scenarios" too.<br><br>Iulian<br><br></div></blockquote></div></body></html>