Hello, <br><br>I would like to use parseval&#39;s theorem (as described in a document called: <span style="font-size: 12pt; font-family: &quot;Times New Roman&quot;;" lang="EN-US">Error Reporting Recommendations: A Report of the Standards and Criteria Committee, Adopted by the IXS Standards and Criteria Committee July 26, 2000</span> ) to quantify the statistical noise in my spectra. <br>
<br>In section 3 (as shown in the attachment), it says that for the formula to work, the forward FT has to be normalized by  sqrt(deltak/Pi). (delta k is the spacing of points in k space)<br><br>What is the normalization used for FFT in athena? if it is not sqrt(deltak/Pi), what is it? how does the parseval theorem formula need to be modified as a function of FT normalization?<br>
<br>Many thanks for answers!<br><br>Regina<br>