RedNoise_Confidence​Levels

Function testing the amount of red noise in a signal and calculating the confidence levels

Function testing the amount of red noise in a signal, and calculating the
confidence levels using three methods :
-based on the spectral analysis of nsim simulations of red noise, using
Monte-Carlo algorythme
-based on a chi2 test performed on the mean spectrum of the nsim red noise
calculated
-based on the chi2 test performed on the theoretical estimate of the red noise spectrum.