polynomial matrix long division
[x]=ldiv(n,d,k)
:n,d two real polynomial matrices : :k integer :
x=ldiv(n,d,k) gives the k first coefficients of the long division of n by d i.e. the Taylor expansion of the rational matrix [nij(z)/dij(z)] near infinity.
Coefficients of expansion of nij/dij are stored in x((i-1)*n+k,j) k=1:n
wss=`ssrand`_(1,1,3);[a,b,c,d]=`abcd`_(wss);
wtf=`ss2tf`_(wss);
x1=ldiv(`numer`_(wtf),`denom`_(wtf),5)
x2=[c*b;c*a*b;c*a^2*b;c*a^3*b;c*a^4*b]
wssbis=`markp2ss`_(x1',5,1,1);
wtfbis=`clean`_(`ss2tf`_(wssbis))
x3=ldiv(`numer`_(wtfbis),`denom`_(wtfbis),5)