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<p>Hi,<br>
</p>
<p>Might it be worth trying Spiral?</p>
<p><a class="moz-txt-link-freetext" href="https://users.ece.cmu.edu/~franzf/papers/fftx-ecp-poster2019_rows.pdf">https://users.ece.cmu.edu/~franzf/papers/fftx-ecp-poster2019_rows.pdf</a></p>
<p><a class="moz-txt-link-freetext" href="http://users.ece.cmu.edu/~franzf/papers/08510983_Spiral_IEEE_Final.pdf">http://users.ece.cmu.edu/~franzf/papers/08510983_Spiral_IEEE_Final.pdf</a></p>
<p><a class="moz-txt-link-freetext" href="http://www.spiral.net/doc/usermanual/gettingstarted.html#installing-spiral">http://www.spiral.net/doc/usermanual/gettingstarted.html#installing-spiral</a></p>
<p>Benson<br>
</p>
<div class="moz-cite-prefix">On 8/10/19 6:56 PM, Erik Lindahl wrote:<br>
</div>
<blockquote type="cite"
cite="mid:CAEJJM8Eu6Z_Y19WP1Gs=ysKQJNfpAE0+dVEktP656gvR3Eyj7Q@mail.gmail.com">
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<div dir="ltr">Hi Peter,
<div><br>
</div>
<div>All our FFTs employ the same standard output formats as
used by e.g. FFTW and and MKL, so for the full documentation
it's probably easiest to read there.</div>
<div><br>
</div>
<div>Short story: All values are stored as proper real+complex
parts (i.e., 2 real values), so depending on input size the
output array might be larger. For in-place R2C transforms that
usually means padding (but not out-of-place ones).</div>
<div><br>
</div>
<div>Cheers,</div>
<div><br>
</div>
<div>Erik</div>
</div>
<br>
<div class="gmail_quote">
<div dir="ltr" class="gmail_attr">On Sat, Aug 10, 2019 at 10:36
AM Peter Kasson <<a href="mailto:kasson@virginia.edu"
moz-do-not-send="true">kasson@virginia.edu</a>> wrote:<br>
</div>
<blockquote class="gmail_quote" style="margin:0px 0px 0px
0.8ex;border-left-width:1px;border-left-style:solid;border-left-color:rgb(204,204,204);padding-left:1ex">
<div dir="ltr">Hi developers,
<div> The doxygen docs are a little ambiguous
on gmx_fft_2d_real(), and the source doesn't offer much
clarification because we're wrapping external libraries.
Given a real-to-complex 2D FFT on a grid of size x by y,
is the output a complex grid of size x by y also? There
are comments about in-place FFT (which I'm not doing)
taking a 5*4 real array and writing a 5*2 complex array.</div>
<div><br>
</div>
<div>(The context of this is trying to compute power spectra
for an analysis routine.)</div>
<div><br>
</div>
<div>Thanks,</div>
<div>--Peter<br clear="all">
<div>
<div dir="ltr"
class="gmail-m_-5959976848667769378gmail_signature">
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<div>
<div dir="ltr">
<div><br>
----------------------------------------------------------------------<br>
Peter Kasson, MD, PhD<br>
Associate Professor<br>
Departments of Molecular Physiology and
Biological Physics<br>
and of Biomedical Engineering<br>
University of Virginia<br>
</div>
</div>
</div>
</div>
</div>
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<br clear="all">
<div><br>
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-- <br>
<div dir="ltr" class="gmail_signature">
<div dir="ltr">
<div>
<div dir="ltr">
<div>
<div dir="ltr">
<div>
<div dir="ltr">
<div>Erik Lindahl <<a
href="mailto:erik.lindahl@dbb.su.se"
target="_blank" moz-do-not-send="true">erik.lindahl@dbb.su.se</a>></div>
<div>Professor of Biophysics, Dept. Biochemistry
& Biophysics, Stockholm University</div>
<div>Science for Life Laboratory, Box 1031, 17121
Solna, Sweden</div>
</div>
</div>
</div>
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