# Typo in docs of InverseFourierSequenceTransform & FourierCoefficient ?

GROUPS:
 Documentation for both functions says "FourierCoefficient is the same as InverseFourierSequenceTransform" and proceeds to show an example where they happen to give the same results (only because they're applied to an even function). In fact the two functions aren't the same. They have opposite signs in the exponent in the integral.
9 months ago
6 Replies
 Welcome to Wolfram Community! Please make sure you know the rules: https://wolfr.am/READ-1STPlease do not use word "bug" in titles unless it is confirmed. If you are sure you found a bug please report via regular channels:http://www.wolfram.com/company/contact
9 months ago
 There's a feedback link at the bottom of each online documentation page. Why don't you use that?
9 months ago
 I frequently use that feedback link.BTW, I wish you could also leave comments (like in the MySQL documentation).
 Yes, I suppose a slight change in the docs is in order; terming it a bug is rather extreme, tho.To assuage one of your objections, let us use a manifestly unsymmetric function: f[w_] := Exp[i w] UnitStep[w] Now, evaluate the following in sequence: InverseFourierSequenceTransform[f[w], w, n] FourierCoefficient[f[w], w, n, FourierParameters -> {1, -1}] FourierCoefficient[f[w], w, n] InverseFourierSequenceTransform[f[w], w, n, FourierParameters -> {1, -1}] Stare at the four expressions just generated for a full minute.Having done so, go back to the documentation for InverseFourierSequenceTransform[] and FourierCoefficient[]. Note well the bullet points under "Details and Options" the description for the FourierParameters option for both functions. Compare and contrast.After all that, if you still feel motivated to complain to Support, you should now be able to write a more refined report armed with the information you gained from doing that suggested activity.