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diff --git a/macros/sos2ss.sci b/macros/sos2ss.sci
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+//Author: Parthasarathi Panda
+//parthasarathipanda314@gmail.com
+function [A,B,C,D]=sos2ss(sos,g)
+    [nargout,nargin]=argn();
+    if nargin==1 then
+        g=1;
+    end
+    if type(sos)~=1 | type(g)~=1 then
+        error('check the data type of input'); //to check if the inputs are real/complex arrays
+    end
+    if size(g)~=[1,1] then
+        error('check the data type of input'); //to check that n is single dimensional
+    end
+    //checking if sos is a 6 column matrix
+    [d,j]=size(sos);
+    if j~=6 then
+        error('sos should be a 6-column matrix');
+    end
+    
+    num=[1];
+    den=[1];
+    //convolving the numerator and denominator to get the coefficient of the numerator and the denominator at the top and bottom
+    for i=[1:d]
+        num=convol(num,sos(i,1:3));
+        den=convol(den,sos(i,4:6));
+    end
+    
+    if den(t)==0 then
+        error('improper transfer function check input');
+    end
+    
+    t=2*d+1; //polynomial degree
+    A=zeros(t-1,t-1);
+    if t>2 then
+        A(2:(t-1),1:(t-2))=eye(t-2,t-2);
+    end
+    A(1,:)=-1*den(2:t)/den(1); 
+    B=zeros(t,1);
+    B(1)=1/den(1); //constructing (A,B) in canonical controllable form
+
+    C=g*(num(2:t)-den(2:t)*num(1)/den(1));//appropiate C and D
+    D=g*num(1)/den(1);
+    
+endfunction