
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 f_{1} and f_{2} is defined as
1/(f_{2} – f_{1}) ∫_{f1}^{f2} 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+n1} (x_{i} – μ)^{2} 
where n is the number of band centres between f_{1} and f_{2}. Note the "minus 1".
© ppgb, October 16, 1999