I initially didn't think that its necessary to talk about the source of the lists "rep" and "Edge" and hence I didn't include those in the question. I thought the question could be answered in the abstract.
But then for me it gives me this "error" message quoted in the first post for q=2, n=3 or q=2, n=4 or q=3, n=3. And hence I was wondering as to what is the error that SAGE is complaining about. If it is just a matter of a long running time then leaving it to run for hours or days should have produced the answer. But that is not the case. Or can you suggest any optimization that can help the running time of the last block ? On Thursday, May 14, 2015 at 5:08:54 PM UTC-5, David Joyner wrote: > > On Thu, May 14, 2015 at 4:43 PM, Phoenix <[email protected] > <javascript:>> wrote: > > The time trouble starts at the point in the code where it doesn't matter > > where the permutation matrices comes from. > > > > What the main part does is basically this. > > > > Given any set of matrices of dimensional k it produces by the "product" > and > > "zip" command all possible ways of distributing those matrices over the > set > > of edges of the graph of size n . > > One fixes some arbitrary orientation for each of the edges. It doesn't > > matter what. > > Now it creates a matrix M of size kn as a n x n array of size k matrices > as > > follows : for the (a,b) edge is in the oriented edge list it (1) places > into > > the (a,b) array position the matrix that was assigned to that edge and > (2) > > it places into the (b,a) position the inverse of that matrix. Now it > > calculates the characteristic polynomial of this M and keeps adding it > up > > over all possible ways of distributing the matrices over the edges. > > > > > > I ran the block below and it ran without error until I killed it (note > the additional print statement at the end) To me this suggests there > is no problem with your code. There might be a problem managing a > large list. If that is the case, you'll need to think more about other > ways to do the computation. > > > To the OP: if you had simply supplied the block below initially, as > William Stein suggested, you would have saved both your time and ours. > > > > q=2; n=4 > > g = graphs.CompleteBipartiteGraph(n, n) > > Edge = [] > for (a,b,c) in g.edges (): > Edge.append ( (a,b) ) > > #This is how "rep" is created, > > Fq2 = [] > for i in range (q): > for j in range (q): > Fq2.append (matrix([[i],[j]])) > > SL2Fq = [] > for i1 in range (q): > for i2 in range (q): > for i3 in range(q): > for i4 in range (q): > if (i4*i1-i2*i3)% q == 1 : > SL2Fq.append ( matrix( [ [i1, i2],[i3,i4] ] ) ) > > rep = [] > for Y in SL2Fq: > M = [] > for A in Fq2: > B = (Y*A)%q > row = [] > for C in Fq2: > if B == C: > row.append ([1]) > else: > row.append ([0]) > M.append(flatten(row)) > rep.append (matrix(M).transpose()) > > P = 0 > from itertools import product > from itertools import izip > > for X in product(rep,repeat = len (Edge)): > k = izip(Edge,X) > M = [[matrix(q^2, q^2, 0)]*(2*n) for ell in range(2*n)] > for ((a,b),Y) in k: > M [a][b] = Y > M [b][a] = Y.inverse() > Z = block_matrix(M) > P = P + Z.charpoly(x) > print P > > > > -- > > You received this message because you are subscribed to the Google > Groups > > "sage-support" group. > > To unsubscribe from this group and stop receiving emails from it, send > an > > email to [email protected] <javascript:>. > > To post to this group, send email to [email protected] > <javascript:>. > > Visit this group at http://groups.google.com/group/sage-support. > > For more options, visit https://groups.google.com/d/optout. > -- You received this message because you are subscribed to the Google Groups "sage-support" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send email to [email protected]. Visit this group at http://groups.google.com/group/sage-support. For more options, visit https://groups.google.com/d/optout.
