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Developer Documentation |
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SUMMARY: fields | routine DETAILS: routine | ||||||||||
./toolbox dcfft.pro
dcfft |
function dcfft(real[, imag], [/inverse], [bdrop=integer], [edrop=integer]) |
Do an FFT (forward or inverse) of a data container. For a real-to-complex FFT, only one data container is given in the arguments. For a complex-to-complex FFT, the real part comes from the first data container and the imaginary part comes from the second data container. The returned value is always a complex array containing the results of the FFT. The input data containers are not changed by this function. It is up to the caller to determine what to do with this result (e.g. further calculations, store the real part in one data container and the imaginary part in another, etc).
This uses the builtin IDL FFT function.
For spectral-line data, when inverse is not set (the default) the builtin IDL inverse flag is used. This means that when dcfft is called with its default arguments and the input data container is a spectrum, the IDL FFT will convert properly from the frequency domain to the time domain (which is actually an inverse FFT). When inverse is set, the builtin IDL inverse flag is not set. This may be confusing to IDL users, but it will be familiar to former UniPOPS users.
For continuum data, the inverse flag here is exactly the same as the inverse flag in the builtin IDL function.