<html><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; ">Hi MPICH-users,<div><br></div><div>to merge to applications I have to create a communicator with coordinates in a reversed ordering of the coordinates than the default in MPI.</div><div>E.g.: The default MPI layout sets the ranks of the communicators to first in z than in y than in x direction, like:</div><div><br></div><div>y</div><div>^<br>| 2-4-6<br>| 1-3-5<br>|--------> x<br><br>Now I want to change the ordering to loop first in x than in y, like:</div><div><br>y<br>^<br>| 4-5-6<br>| 1-2-3<br>|--------> x</div><div><br></div><div>So far I can create a cartesian communicator and test its coords with </div><div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; font: normal normal normal 11px/normal Monaco; "><span style="color: rgb(127, 0, 85); ">int</span> dims[3] = {0,0,0};</div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; font: normal normal normal 11px/normal Monaco; "><span style="color: rgb(127, 0, 85); ">int</span> ndims=3;</div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; font: normal normal normal 11px/normal Monaco; "><span style="color: rgb(100, 40, 128); ">MPI_Dims_create</span>(NumberOfProcessors, ndims, dims);</div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; font: normal normal normal 11px/normal Monaco; "><span style="color: rgb(127, 0, 85); ">int</span> false = 0; <span style="color: rgb(127, 0, 85); ">int</span> true = 1;</div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; font: normal normal normal 11px/normal Monaco; "><span style="color: rgb(127, 0, 85); ">int</span> periods[3] = { false, false, true };</div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; font: normal normal normal 11px/normal Monaco; "><span style="color: rgb(127, 0, 85); ">int</span> reorder = true;</div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; font: normal normal normal 11px/normal Monaco; "><span style="color: rgb(0, 80, 50); ">MPI_Comm</span> MyComm;</div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; font: normal normal normal 11px/normal Monaco; "><span style="color: rgb(100, 40, 128); ">MPI_Cart_create</span>(MPI_COMM_WORLD, ndims, dims, periods, reorder, &MyComm);</div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; font: normal normal normal 11px/normal Monaco; "><span style="color: rgb(100, 40, 128); ">MPI_Cart_coords</span>(MyComm, LocalRank, ndims, coords);</div></div><div><br></div><div>But how can I get access to change either the current rank or the associated coords?</div><div><br></div><div>Thanks for your help in advance,</div><div>Rolf</div></body></html>