[EMAIL PROTECTED] (Robert J. MacG. Dawson) wrote in message news:<[EMAIL PROTECTED]>... > Shareef Siddeek wrote: > > > > Hi Simon, > > A side issue to this thread. Why certain types of noises in time series analysis > > are called 'white noises'? Is there any other colors attached to different types > > of noises? Are there green or red noises? > > It's a metaphor. White = uniform (in a certain sense) mixture of all > frequencies. > > One does sometimes hear of pink noise, which is the result of smoothing > off the higher frequencies. > > "Red" or "green" would be monochromatic, so not noise. > > -Robert Dawson > .
Strictly speaking from a linguistic point of view I suppose you're right about red noise, but generally in the geosciences red noise is a term applied to data with strong short range autocorrelations, like day-to-day temperatures (and more power at low frequencies than high frequencies). It doesn't have to be monochromatic. Arguably an example of loose use of the language, I admit. Regards, Russell . . ================================================================= Instructions for joining and leaving this list, remarks about the problem of INAPPROPRIATE MESSAGES, and archives are available at: . http://jse.stat.ncsu.edu/ . =================================================================
