AEKI2c.TXT 0 8 128 1 AEKI2cdsp.TXT

calculation of the voltage PSD, current PSD, and Zn of a time record 
divided in 1 or several sections

file_in hanning (0 = no, 1 = yes) nb_section nbpoint_section 
detrend (0 = no, 1 = linear) file_out

no character "blank" in the names of file_in and file_out
nbpoint_section must be a power of 2

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When detrend = 1, information is given in the final window on the 
importance of the drift in the voltage and current time records:

- SD is the standard deviation of the detrended signal 
  (SD is wrong if calculated on the raw signal because of the 
   influence of the drift),

- aT is the signal drift over the duration T of the time record 
  (a is the slope of the linear drift),

- drift/Vpp (or drift/App) is the ratio aT/(4 SD): 4 SD represents 
  the peak-to-peak amplitude of the fluctuation (indeed, the 
  probability that the amplitude of a Gaussian signal with mean 0 
  ranges between -2 SD and +2 SD is 95.4 %, which is close to 100 %). 
  This ratio compares the signal drift and the amplitude of the 
  fluctuations. It only indicates if the drift was important in the 
  raw data (roughly, the drift is important when the ratio is higher 
  than 0.1). It brings no information on the linearity of the drift 
  that must be checked by looking at the time record.