I have already sent, but I dont answer ... because I expect please only if anyelse can help me iff a time ...
2011/9/28 David Joyner <wdjoy...@gmail.com> > On Wed, Sep 28, 2011 at 6:12 PM, Juan Grados <juan...@gmail.com> wrote: > > Hi David, > > > > Yes I understand, but now I think that have a logic problem in algorithm, > > but I don't know where ... i "copying lines" from [Ict2011], ... > > > I would just email the author of the paper and ask him. > > > > 2011/9/28 David Joyner <wdjoy...@gmail.com> > >> > >> On Wed, Sep 28, 2011 at 5:58 PM, Juan Grados <juan...@gmail.com> wrote: > >> > help please! > >> > >> > >> They did seem to solve your problem, didn't they? > >> Do you not understand the English? Do you simply disagree? > >> If you don't understand the English, please find someone who can > >> translate. > >> > >> Did you find another error after fixing the problem they told about? > >> > >> Please be very clear exactly what it is you are having a problem > >> understanding in this thread. > >> > >> > >> > > >> > 2011/9/28 Juan Grados <juan...@gmail.com> > >> >> > >> >> in the end line > >> >> print sigma.roots(), > >> >> always give empty vector, here sigma.roots() should nonzero vector > >> >> 2011/9/28 Juan Grados <juan...@gmail.com> > >> >>> > >> >>> Hi thanks for your answers, > >> >>> I used _inverter_, _mul_, _add_ etc, because apparently > >> >>> the implementation work fine but only "apparently", > >> >>> i think that the essencial problem is with _invert_ method, > >> >>> but now I used inverse_mod , but I dont > >> >>> where are the error, I implemented Berlekamp Algorithm too, from > >> >>> [Ict2011], its inside worksheet, > >> >>> this work fine, but Patterson Algorithm no, > >> >>> please help me with this implementation > >> >>> ''' > >> >>> ALGORITHM: > >> >>> The following two algorithms are in [Ict2011] > >> >>> REFERENCES: > >> >>> .. [Ict2011] How SAGE helps to implement Goppa Codes and McEliece > >> >>> PKCSs > >> >>> URL > >> >>> > >> >>> : > http://www.google.com/url?sa=t&source=web&cd=2&ved=0CCUQFjAB&url=http%3A%2F%2Fwww.weblearn.hs-bremen.de%2Frisse%2Fpapers%2FICIT11%2FRisse526ICIT11.pdf&ei=Q-yCTpK5C82cgQfj3803&usg=AFQjCNGEZ7SuMf1WKPrdkxvJMfiSaSqO1w&sig2=3RM25hfPNHCveQvdjTn4Iw > >> >>> ''' > >> >>> def encode(u): > >> >>> return u*G_Goppa; > >> >>> #this is the Berlekamp > >> >>> def decode(y,m,N,H_gRS): > >> >>> tt = var('z') > >> >>> s = H_gRS*y.transpose(); > >> >>> if s==matrix(Phi,H_gRS.nrows(),1): > >> >>> return y; > >> >>> b = PR([s[_,0] for _ in range(s.nrows())]); > >> >>> > >> >>> # > >> >>> bigN = m; > >> >>> sigma = vector(PolynomialRing(Phi,tt),bigN+2); > >> >>> omega = vector(PolynomialRing(Phi,tt),bigN+2); > >> >>> delta = vector(PolynomialRing(Phi,tt),bigN+2); > >> >>> sigma[-1+1] = PR(0); > >> >>> sigma[0+1] = PR(1); > >> >>> flag = 2*bigN; # exponent flags rational 1/z > >> >>> omega[-1+1] = z**flag; > >> >>> omega[0+1] = PR(0); > >> >>> # init mu and delta > >> >>> mu = -1; delta[-1+1] = 1; > >> >>> for i in range(bigN): > >> >>> delta[i+1] = (sigma[i+1]*b).coeffs()[i]; > >> >>> sigma[i+1+1] = > >> >>> sigma[i+1](z)-z**(i-mu)*(delta[i+1]/delta[mu+1])*sigma[mu+1](z); > >> >>> if (omega[mu+1].degree()==flag): > >> >>> omega[i+1+1] = > >> >>> omega[i+1](z)-(delta[i+1]/delta[mu+1])*z**(i-mu-1); > >> >>> else: > >> >>> omega[i+1+1] > >> >>> =omega[i+1](z)-z**(i-mu)*(delta[i+1]/delta[mu+1])*omega[mu+1](z); > >> >>> ord = max(sigma[i+1].degree(),1+omega[i+1].degree()); > >> >>> if (delta[i+1]<>0)and(2*ord<=i): > >> >>> mu = i; > >> >>> ELP = sigma[bigN+1]; # ErrorLocatorPolynomial > >> >>> n = G_Goppa.nrows(); > >> >>> ee = vector(F,[0 for _ in range(n)]); > >> >>> for i in range(N): > >> >>> if (ELP(x**i)==Phi(0)): # an error occured > >> >>> print 'error position',N-i > >> >>> return 0; > >> >>> def split(p): > >> >>> # split polynomial p over F into even part po > >> >>> # and odd part p1 such that p(z) = p2 (z) + z p2 (z) > >> >>> Phi = p.parent() > >> >>> p0 = Phi([sqrt(c) for c in p.list()[0::2]]); > >> >>> p1 = Phi([sqrt(c) for c in p.list()[1::2]]); > >> >>> return (p0,p1); > >> >>> m = 4 > >> >>> F.<x> = GF(2) > >> >>> Phi.<x> = GF(2^m); > >> >>> PR = PolynomialRing(Phi,'z'); > >> >>> print 'PR is',PR; > >> >>> N = 2^m - 1; > >> >>> codelocators = [x^i for i in range(N)] > >> >>> print(codelocators) > >> >>> X = PolynomialRing(Phi,repr('z')).gen(); > >> >>> g = X^2+X+x^3; # goppa polynomial > >> >>> print 'goppa polinomial',g > >> >>> if g.is_irreducible(): > >> >>> print 'g(z) =',g,'is irreducible'; > >> >>> for i in range(N): > >> >>> if g(codelocators[i])==Phi(0): > >> >>> print 'alarm: g(alpha_'+str(i)+')=0'; > >> >>> H_gRS = matrix([[codelocators[j]^(i) for j in range(N)] for i in > >> >>> range(m)]); > >> >>> H_gRS = H_gRS*diagonal_matrix([ 1/g(codelocators[i]) for i in > >> >>> range(N)]); > >> >>> print H_gRS > >> >>> H_Goppa = matrix(F,m*H_gRS.nrows(),H_gRS.ncols()); > >> >>> for i in range(H_gRS.nrows()): > >> >>> for j in range(H_gRS.ncols()): > >> >>> be = bin(eval(H_gRS[i,j].int_repr()))[2:]; > >> >>> be = '0'*(m-len(be))+be; be = list(be); > >> >>> H_Goppa[m*i:m*(i+1),j]=vector(map(int,be)); > >> >>> Krnl = H_Goppa.right_kernel(); > >> >>> G_Goppa = Krnl.basis_matrix(); > >> >>> print H_Goppa > >> >>> k = G_Goppa.nrows() > >> >>> u = vector(F,[randint(0,1) for _ in range(k)]); > >> >>> c = encode(u); > >> >>> e = vector(F,H_gRS.ncols()); # e = zero vector > >> >>> e[3]=1 > >> >>> y = vector(F,H_gRS.ncols()); > >> >>> y = c + e > >> >>> print 'berlekamp algorithm' > >> >>> decode(y,m,N,H_gRS) > >> >>> print 'patterson algorithm' > >> >>> #adicionando error > >> >>> s = H_gRS*y.transpose(); > >> >>> sP = PR([s[_,0] for _ in range(s.nrows())]); > >> >>> print 'g=',g > >> >>> g0g1 = split(g); > >> >>> w = g0g1[0]*(((g0g1[1]).inverse_mod(g))) > >> >>> print 'w=',w > >> >>> T0T1 = split(sP.inverse_mod(g) + X); > >> >>> R = T0T1[0]+(w)*(T0T1[1]) > >> >>> print 'R',R > >> >>> (d1,u,v) = xgcd(1,R); # where d = gcd(1,R) = 1 > >> >>> a = g*u; b = g*v; > >> >>> sigma = (a^2+X*(b^2)); > >> >>> print sigma.roots() > >> >>> > >> >>> > >> >>> 2011/9/28 D. S. McNeil <dsm...@gmail.com> > >> >>>> > >> >>>> > This is definitely not a bug. The definition of the _add_ > method > >> >>>> > absolutely demands that both inputs have exactly the same parent. > >> >>>> > In > >> >>>> > the above instance, the left hand input (=1) has parent ZZ, and > the > >> >>>> > right hand input (=SR(2)) has parent the symbolic ring. > >> >>>> > >> >>>> Yeah, I know that-- it's the violation of that assumption which > >> >>>> ultimately crashed the OP's code, after all. > >> >>>> > >> >>>> I guess I've inherited the bias from Python that users shouldn't be > >> >>>> able to segfault the interpreter from pure Python code. > >> >>>> Anything Cythonic probably falls into the Sage equivalent of the > >> >>>> "ctypes exception" class, and I guess you can get the same crash > with > >> >>>> any non-typechecking cpdef'd object, but it still feels wrong. > >> >>>> > >> >>>> Meh. > >> >>>> > >> >>>> > >> >>>> Doug > >> >>>> > >> >>>> -- > >> >>>> To post to this group, send email to sage-support@googlegroups.com > >> >>>> To unsubscribe from this group, send email to > >> >>>> sage-support+unsubscr...@googlegroups.com > >> >>>> For more options, visit this group at > >> >>>> http://groups.google.com/group/sage-support > >> >>>> URL: http://www.sagemath.org > >> >>> > >> >>> > >> >>> > >> >>> -- > >> >>> > --------------------------------------------------------------------- > >> >>> Juan del Carmen Grados Vásquez > >> >>> Laboratório Nacional de Computação Científica > >> >>> Tel: +55 24 2233-6260 > >> >>> (http://www.lncc.br/) > >> >>> http://juaninf.blogspot.com > >> >>> > --------------------------------------------------------------------- > >> >> > >> >> > >> >> > >> >> -- > >> >> --------------------------------------------------------------------- > >> >> Juan del Carmen Grados Vásquez > >> >> Laboratório Nacional de Computação Científica > >> >> Tel: +55 24 2233-6260 > >> >> (http://www.lncc.br/) > >> >> http://juaninf.blogspot.com > >> >> --------------------------------------------------------------------- > >> > > >> > > >> > > >> > -- > >> > --------------------------------------------------------------------- > >> > Juan del Carmen Grados Vásquez > >> > Laboratório Nacional de Computação Científica > >> > Tel: +55 24 2233-6260 > >> > (http://www.lncc.br/) > >> > http://juaninf.blogspot.com > >> > --------------------------------------------------------------------- > >> > > >> > -- > >> > To post to this group, send email to sage-support@googlegroups.com > >> > To unsubscribe from this group, send email to > >> > sage-support+unsubscr...@googlegroups.com > >> > For more options, visit this group at > >> > http://groups.google.com/group/sage-support > >> > URL: http://www.sagemath.org > >> > > > > > > > > > -- > > --------------------------------------------------------------------- > > Juan del Carmen Grados Vásquez > > Laboratório Nacional de Computação Científica > > Tel: +55 24 2233-6260 > > (http://www.lncc.br/) > > http://juaninf.blogspot.com > > --------------------------------------------------------------------- > > > > -- > > To post to this group, send email to sage-support@googlegroups.com > > To unsubscribe from this group, send email to > > sage-support+unsubscr...@googlegroups.com > > For more options, visit this group at > > http://groups.google.com/group/sage-support > > URL: http://www.sagemath.org > > > -- --------------------------------------------------------------------- Juan del Carmen Grados Vásquez Laboratório Nacional de Computação Científica Tel: +55 24 2233-6260 (http://www.lncc.br/) http://juaninf.blogspot.com --------------------------------------------------------------------- -- To post to this group, send email to sage-support@googlegroups.com To unsubscribe from this group, send email to sage-support+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-support URL: http://www.sagemath.org
