This is a question about 'freqt' command from anonymous.

Dear Prof. Tamamori,

I have two small questions regarding the latest version of SPTK,

(I know this should be asked in the forum but I have seen it is abondoned)

in the file

"_freqt.c"

in the function

freqt

regarding the "for" loop towards the end of the function :

I have two questions :

1) shoudn't there be a minus instead of a plus before the "a" inside the loop

my reason for asking : I understand this is the implementation of

the allpass transfer function the warps the phase, but the interpretation of

z^-1-alpha/1-alpha z^-1

should be

y = x + alpha(y - x)

and in your code it seems you put a minus before the alpha

2) what is the reason for multiplying

b*d

where

b=1-alpha^2

when the value of g is computed

shouldn't b=1 ?