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<div>Thanks Matt and Dave for the explanation, that is very helpful. </div>
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<div>Best</div>
<div>Sean<br>
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<div class="gmail_quote">On Thu, May 12, 2016 at 8:58 AM -0700, "Dave May" <span dir="ltr">
<<a href="mailto:dave.mayhem23@gmail.com" target="_blank">dave.mayhem23@gmail.com</a>></span> wrote:<br>
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Matt beat me to the punch... :D<br>
Anyway, here is my more detailed answer.<br>
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<div>Thanks! Somehow I missed DM{Get,Create}LocalVector(). BTW what is the difference between the Get and Create versions? It is not obvious from the documentation.</div>
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<div>The DMDA contains a pool of vectors (both local and global) which can be re-used by the user. This avoids the need to continually allocate and deallocate memory. Thus, the Get methods are simply an optimization.<br>
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The Get methods retrieve from the pool, a vector which isn't currently in use. In this case, You can think of Restore as returning the vector back to the pool to be used somewhere else.<br>
If all vectors in the pool are in use, a new one will be allocated for you. In this case, Restore will actually deallocate memory.<br>
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<div>Since Get methods may return vectors which have been used else where in the code, you should always call VecZeroEntries() on them.<br>
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<div>The Create methods ALWAYS allocate new memory and thus you ALWAYS need to call Destroy on them. Vectors obtained via VecCreate() will always be initialized with 0's.<br>
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<div>Thanks,<br>
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<div> Dave<br>
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<div>Also, can you explain the difference between DMDAVecGetArrayDOF and DMDAVecGetArrayDOFRead?</div>
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<div>Thanks again,</div>
<div>Sean</div>
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<div>Thanks,</div>
<div> Dave</div>
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<div>Thanks very much!</div>
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<div>Sean Dettrick</div>
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