db's profile - activity

sorry for the poor formatting, don't know what happened

I am trying to install a new experimental package from within sage (asymptote in this case) and get the following error message:

sage: sage.misc.package.install_package('asymptote-1.29') Attempting to download package asymptote-1.29

Checking online list of optional packages. [Traceback (most recent call last): File "", line 29, in File "/misc/ada2/visit/betea/Programs/sage-5.8/local/lib/python/urllib.py", line 244, in retrieve tfp = open(filename, 'wb') IOError: [Errno 20] Not a directory: '/dev/stdout' Error: failed to download http://www.sagemath.org/spkg/optional..., aborting

Any help?

Is there a correct way to compute skew Macdonald polynomials in sage? The routine skew_by does not seem to give the right answer (far from it). Probably due to the fact that "zee" is not defined properly somewhere.

If I have a polynomial p in variables $x_0,...,x_n$, how do I specialize the algebra appropriately to substitute values for $x_i$'s? For example, how do I compute $p(1,1,...,1)$? Or replace $x_i$ by $q^i$ ($q$ a parameter) so to compute $p(1,q,...,q^n)$? In Mathematica, if the variables were x[[i]], one could do "./x[[i]] -> q^i //Simplify" and it is the equivalent of this replace and simplify that I am looking for.

This is coming from symmetric polynomials/functions theory and I know some of the specializations are built in, but at the end of the day I want to try small examples with different specializations than what is already built in.