A query to the selected Ltas object.
the standard deviation (in dB) of the LTAS within a specified frequency domain.
The standard deviation between the frequencies f1 and f2 is defined as
|1/(f2 – f1) ∫f1f2 df (x(f) – μ)2|
where x(f) is the LTAS as a function of frequency, and μ its mean. For our discrete Ltas object, the standard deviation is approximated by
|1/(n–1) ∑i=m..m+n-1 (xi – μ)2|
where n is the number of band centres between f1 and f2. Note the "minus 1".
© ppgb, October 16, 1999