<html><head><meta http-equiv="Content-Type" content="text/html charset=utf-8"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;" class="">Yes, it makes perfect sense. <div class=""><br class=""></div><div class="">The issue is that the global size of my ISs are the same, but it’s the local size that is different (because of different DMDAs)<div class=""><div class=""><br class=""></div><div class="">Is there an easy way to put both IS’s on the same parallel layout. ISCopy doesn’t work in that case.</div><div class=""><br class=""></div><div class="">Randy</div><div class=""> </div><div class=""><div><blockquote type="cite" class=""><div class="">On Feb 19, 2016, at 4:39 PM, Matthew Knepley <<a href="mailto:knepley@gmail.com" class="">knepley@gmail.com</a>> wrote:</div><br class="Apple-interchange-newline"><div class=""><div dir="ltr" class=""><div class="gmail_extra"><div class="gmail_quote">On Fri, Feb 19, 2016 at 6:33 PM, Randall Mackie <span dir="ltr" class=""><<a href="mailto:rlmackie862@gmail.com" target="_blank" class="">rlmackie862@gmail.com</a>></span> wrote:<br class=""><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">I am trying to do a VecScatter of a subset of elements from a global vector on one DMDA to a global vector on a different DMDA (different sized DMDAs).<br class="">
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I thought what made sense was to create a parallel IS using the local to global mapping obtained from the two DMDAs so that the local portion of each IS contained only the values on that processor.<br class="">
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This works fine as long as the local size of the two IS’s are the same.<br class="">
<br class="">
But, say I have a situation like this:<br class="">
<br class="">
DMDA 1:<br class="">
proc 1: 1 value to scatter<br class="">
proc 2: 7 values to scatter<br class="">
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DMDA 2:<br class="">
proc 1: 4 values to get<br class="">
proc 2: 4 values to get<br class="">
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This doesn’t work because VecScatterCreate says the local size of the IS’s must be the same.<br class="">
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Is the only way to set up this VecScatter to create a sequential IS on each processor of length 8 and duplicate the values?<br class=""></blockquote><div class=""><br class=""></div><div class="">The two inputs are</div><div class=""><br class=""></div><div class=""> index of input vector --> input of output vector</div><div class=""><br class=""></div><div class="">and you can have as many entries of this map on any process as you want. Clearly, you</div><div class="">need the same number of entires in each IS to make this map meaningful. Does that make</div><div class="">sense?</div></div></div></div></div></blockquote><blockquote type="cite" class=""><div class=""><div dir="ltr" class=""><div class="gmail_extra"><div class="gmail_quote"><div class=""><br class=""></div><div class=""> Thanks,</div><div class=""><br class=""></div><div class=""> Matt</div><div class=""> </div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
Thanks,<br class="">
<br class="">
Randy M.<br class="">
<br class="">
</blockquote></div><br class=""><br clear="all" class=""><div class=""><br class=""></div>-- <br class=""><div class="gmail_signature">What most experimenters take for granted before they begin their experiments is infinitely more interesting than any results to which their experiments lead.<br class="">-- Norbert Wiener</div>
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