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<div>Dear All,</div><div><br></div><div>For the NCL function fft2df, it is noticed that "<span style="font-size: 10.5pt; line-height: 1.5; background-color: window;">The results of </span><strong style="font-size: 10.5pt; line-height: 1.5; background-color: window;">fft2df</strong><span style="font-size: 10.5pt; line-height: 1.5; background-color: window;"> are normalized:
a call to </span><strong style="font-size: 10.5pt; line-height: 1.5; background-color: window;">fft2df</strong><span style="font-size: 10.5pt; line-height: 1.5; background-color: window;"> followed by a
call to </span><a href="https://www.ncl.ucar.edu/Document/Functions/Built-in/fft2db.shtml" style="font-size: 10.5pt; line-height: 1.5; background-color: window;"><strong>fft2db</strong></a><span style="font-size: 10.5pt; line-height: 1.5; background-color: window;"> (or vice-versa) reproduces
the original array within roundoff error." (pls see the NCL website: </span><span style="font-family: ''; font-size: 10.5pt; line-height: 1.5; background-color: window;">https://www.ncl.ucar.edu/Document/Functions/Built-in/fft2df.shtml</span><span style="background-color: window; font-size: 10.5pt; line-height: 1.5;">) </span><span style="background-color: window; font-size: 10.5pt; line-height: 1.5;">The question is, what kind of normalization is applied to fft2df? </span></div><div><span style="background-color: window; font-size: 10.5pt; line-height: 1.5;">Appreciate for your kind help. </span></div><div><span style="font-size: 10.5pt; line-height: 1.5; background-color: window;"><br></span></div><div><span style="font-size: 10.5pt; line-height: 1.5; background-color: window;">Thanks,</span></div><div><span style="font-size: 10.5pt; line-height: 1.5; background-color: window;">Xin</span></div><div><br></div><hr style="width: 210px; height: 1px;" color="#b5c4df" size="1" align="left">
<div><span><div style="MARGIN: 10px; FONT-FAMILY: verdana; FONT-SIZE: 10pt"><div>xin.xu.nju@gmail.com</div></div></span></div>
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