<div class="gmail_quote">On Mon, Jul 11, 2011 at 18:28, Kevin Green <span dir="ltr"><<a href="mailto:Kevin.Green@uoit.ca">Kevin.Green@uoit.ca</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex;">
<div id=":1mn">Essentially, I'm (currently) looking to numerically solve a system of 5 time dependent equations, but only 1 of the fields is involved with spatial derivatives. Now, I've found a couple of ways to do this, either by introducing a Field struct cf. ${PETSC_DIR}/src/snes/examples/tutorials/ex19.c, or by changing one of the various ts examples to use DAVecGetArrayDOF(...). Would there be any performance difference between introducing a Field struct compared to DAVecGetArrayDOF(...)? Intuitively, I would think not...but I suppose I should ask since I'm here anyway.<br>
</div></blockquote><div><br></div><div>I like using field structs because then I get to use names instead of numbers for my fields and because there is one less level of pointer indirection.</div><div> </div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex;">
<div id=":1mn">
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Now the real reason I came: Is there some sort of mask that can be applied to the DAs that would turn off the communication of ghost points for some degrees of freedom? I assume that the communication structures are set up so that only a single message needs to be passed between communicating processes on update, but this still results in passing 5X the data that I have to. Any comment on this would be much appreciated.</div>
</blockquote></div><br><div>DMDASetBlockFills()</div>