Перевод из Mathlab в Scilab

sym Y1z Y2z Y3z Y4z c21 c31 c32 c41 c42 c43 z1 Xz;
eqn1 = Y2z*z1==Y1z;
eqn2 = c21*Y1z+Y3z*z1 == Y2z;
eqn3 = c31*Y1z+c32*Y2z+Xz ==Y3z;
eqn4 = c41*Y1z+c42*Y2z+c43*Y3z == Y4z;
[Y1z,Y2z,Y3z,Y4z] = solve([eqn1, eqn2, eqn3, eqn4],[Y1z,Y2z,Y3z,Y4z])
 
 
 
 
Hz=Y4z/Xz
 
 
 
 [nHz,dHz]=numden(Hz)
 
 
a0=coeffs(nHz,z1)
 
 
 
b0=-1*coeffs(dHz,z1)
 
rp=0.95;fz=0.05;fr=0.075;Pi=3.14;
a0=0;a1=-2*cos(2*Pi*fz);a2=1;b1=-2*cos(2*Pi*fr);b2=rp^2;
 
[c21,c31,c32,c41,c42,c43] = solve([a0==-c43,a1==c21*c43-c42,a2==-c41,b1==-c21-c32,b2==-c31],[c21,c31,c32,c41,c42,c43])
 
c21=1.7822;c31=-0.9025;c32=0;c41=-1;c42=1.9022;c43=0;
 
kol=512;
y2k1=0;y3k1=0;
for k = 0:1:kol
if k==0
Xk=1;
else
Xk=0;
A(k)=y4k;
end
y1k = y2k1;
y2k = c21*y1k+y3k1;
y3k = c31*y1k+c32*y2k+Xk;
y4k = c41*y1k+c42*y2k+c43*y3k;
y2k1 = y2k; y3k1 = y3k;
end
 
plot (A)
 
Y = fft(A, 512);
Pyy = Y.*conj(Y)/512;
plot(Pyy)