IDL Routine: FFT_TOOL QTCM Tool
If you send me <[email protected]> your email address, I'll let you know of any major bugs that are found in this library.
22 Jun 2002: Versions of the tool prior to this date used a version of CALCANOM that computed climatology as a spline-fit to monthly climatology. (This used to be in a file called calcanomL.pro, which is now renamed calcanomL_spl.pro.) It's been found recently that sometimes removing the spline-fit monthly climatology is not enough to remove the fundamental and harmonics of the annual cycle. Thus, those values will still remain which can cause aliasing. Thus, I recommend you use calcanomL_dly.pro, which has the drawback in that it is currently written only for the case of daily data, but appears to remove all the annual cycle contributions more fully.