diff options
Diffstat (limited to 'macros/sos2tf.sci')
| -rw-r--r-- | macros/sos2tf.sci | 43 |
1 files changed, 32 insertions, 11 deletions
diff --git a/macros/sos2tf.sci b/macros/sos2tf.sci index d38a4f7..f674c85 100644 --- a/macros/sos2tf.sci +++ b/macros/sos2tf.sci @@ -1,4 +1,4 @@ -function [B,A] = sos2tf(sos, g) +function [A,B] = sos2tf(sos, g) //This function converts series second-order sections to direct H(z) = B(z)/A(z) form. //Calling Sequence //[B] = sos2tf(sos) @@ -8,7 +8,6 @@ function [B,A] = sos2tf(sos, g) //sos: matrix of real or complex numbers //g: real or complex value, default value is 1 //Description -//This is an Octave function. //This function converts series second-order sections to direct H(z) = B(z)/A(z) form. //The input is the sos matrix and the second parameter is the overall gain, default value of which is 1. //The output is a vector. @@ -19,18 +18,40 @@ function [B,A] = sos2tf(sos, g) // -2 1 2 4 1 //b = // 1 10 0 -10 -1 -funcprot(0); -rhs = argn(2) -if(rhs<1 | rhs>2) +if(argn(2)<1 | argn(2)>2) error("Wrong number of input arguments.") end +if argn(2)==1 then + g=1; +end + + [N,M] = size(sos); + + if M~=6 + error('sos matrix must be N by 6'); + end + + A = 1; + B = 1; + + for i=1:N + A = conv(A, sos(i,1:3)); + B = conv(B, sos(i,4:6)); + end + + nB = length(A); + + while nB & A(nB)==0 + A=A(1:nB-1); + nB=length(A); + end + nA = length(B); + while nA & B(nA)==0 + B=B(1:nA-1); + nA=length(B); + end + A = A * g; - select(rhs) - case 1 then - [B,A] = callOctave("sos2tf",sos) - case 2 then - [B,A] = callOctave("sos2tf",sos,g) - end endfunction |