PS sorry I forgot to mention this happens in 5.7 and 5.11 on a Mac OSX 5.6.8
On Friday, August 16, 2013 10:40:25 PM UTC+1, GaryMak wrote: > > Hi all > > I hesitate to declare a <<bug>>, since it's probably something I cannot > find in the help, but the following is very strange .... > > The following code always seems to output many vectors "quad" of length 4 > each of whose numerical approx "quad.n()" is a vector which only has length > 3 ... > > ########### START CODE ########### > > vec = vector([1.0,1.0,1.0,1.0]) > ZZ = diagonal_matrix([exp(2*pi*I/4)^ii for ii in range(0,4)]) > > for ss in range(0,100): > quad = vector([0,0,0,0]) > for jj in range(0,4): > indy = round(random()*4.0) > if len(quad.n())==3: > print quad.n(), quad > quad = quad + vec*ZZ^indy > > ########### END CODE ########### > > I believe I have eliminated every non-essential: for example, even though > the loop in the vble "jj" is not explicitly used, it nevertheless seems to > be necessary to produce this weird behaviour, as does some complex number > being in the calcs, and most bizarrely, so is the fact that "indy" be > random! (ie it does not happen if I just fix "indy" to be 0,1,2,3 or 4). > > Needless to say, this is rather tricky to work around! > > Many thanks in advance for any help. > > Best regards > > Gary. > > > -- 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/groups/opt_out.
