gusucode.com > 信号处理工具箱 - signal源码程序 > signal\signal\signal\rc2lar.m
function g = rc2lar(k) %RC2LAR Convert reflection coefficients to log area ratios. % G = RC2LAR(K) returns the log area ratios corresponding to the reflection % coefficients, K. % % The log area ratio is defined by G = log((1+k)/(1-k)) , where the K is the % reflection coefficient. % % See also LAR2RC, RC2POLY, RC2AC, RC2IS. % References: % [1] J. Makhoul, "Linear Prediction: A Tutorial Review," Proc. IEEE, % Vol.63, No.4, pp.561-580, Apr 1975. % [2] ITU-T Recommendation G.729 (03/96) % % Author(s): A. Ramasubramanian % Copyright (c) 1988-98 by The MathWorks, Inc. % $Revision: 1.1 $ $Date: 1998/07/24 16:12:12 $ if ~isreal(k), error('Log area ratios not defined for complex reflection coefficients.'); end if max(abs(k)) >= 1, error('All reflection coefficients should have magnitude less than unity.'); end % Use the relation, atanh(x) = (1/2)*log((1+k)/(1-k)) g = -2*atanh(-k); % [EOF] rc2lar.m