paragon's profile - activity

Implementing Subgroups I created my own implementation of a specific group, inheriting from Group, following the pattern

I'm using a MacBook with OS X 10.12.5. Apparently it doesn't come with SSL support: https://github.com/saghul/pythonz/iss.... I have now installed opensll and rebuild sage 8.0. I still get the same error. At least I know that it is a problem with my computer and not with sage.

Thank you! This is what I was hoping for. But unfortunately it didn't fix the problem (see edit).

I want to make a PyPI package for sage, similar to

https://pypi.python.org/pypi/darmonpo...

or

https://pypi.python.org/pypi/surface_...

that can be installed by anyone by typing one line. But trying these out, the installation instructions don't work! I get an error:

$~/SageMath/sage -pip install surface_dynamics
pip is configured with locations that require TLS/SSL, however the ssl module in Python is not available.
Collecting surface_dynamics
  Could not fetch URL https://pypi.python.org/simple/surface-dynamics/: There was a problem confirming the ssl certificate: Can't connect to HTTPS URL because the SSL module is not available. - skipping
  Could not find a version that satisfies the requirement surface_dynamics (from versions: )
No matching distribution found for surface_dynamics

I believe that it is because sage is using pip 8.x, and a later version is required for PyPI. If I try installing surface_dynamics with using pip 9.01, it downloads it (but gives an error later because it is not in sage), so I do think the version is a problem.

I just updated to sage 8.0. Is this planning to be fixed soon? If there is a workaround for me, I guess that is nice, but it defeats the purpose of getting my code hosted on PyPI if I still have to give the users complicated instructions.

Or maybe my sage installation is broken? Do others get the same error?

EDIT: In light of eric_g's answer, I tried installing the developer version of 8.1. Indeed the sage pip is now 9.01, but the same error persists. So I guess my theory about the versions is wrong. It must be something else funny with the sage pip?

This looks like it might be a good way to go if I can figure it out.

I've written some code in sage that implements the strata algebra of the moduli spaces of curves as a sage ring. I hope it will be useful to others. I think that a good way to share it would be to make it an optional, (or perhaps experimental?) sage package.

Is this a good thing to do?

If so, what are the steps?

My code is all in .sage files, but I could easily turn it into .py files if that is better.

The following gives an error:

sym = SymmetricFunctions(QQ)
R.<t> = PowerSeriesRing(sym)

saying that base_ring is not a commutative ring. I can check sym.categories(), and indeed it is not, but I think it should be. Is there an easy way to make this work?

Thanks!

Perfect! It is hidden pretty deep, I would not have found that.

I want something like this, or a way to get the equivalent information:

sage: S.<X,Y> = FreeAlgebra(QQ)
sage: m = X*Y*X^2
sage: m.my_exponents_function()
[(X,1),(Y,1),(X,2)]

or

sage: m.my_factor_function()
[X,Y,X,X]

would be as good or maybe better.

How can I get that information? I've looked over the available methods and can't seem to find anything. This is easy to do with Polynomial Rings.

I guess I could parse the string representation, but shouldn't there be a better way?

I want something like this, or a way to get the equivalent information:

sage: S.<X,Y> = FreeAlgebra(QQ)
sage: m = X*Y*X^2
sage: m.my_exponents_function()
[(X,1),(Y,1),(X,2)]

or

sage: m.my_factor_function()
[X,Y,X,X]

would be as good or maybe better.

How can I get that information? I've looked over the available methods and can't seem to find anything. This is easy to do with Polynomial Rings.

I guess I could parse the string representation, but shouldn't there be a better way?

Is there a nice way to get all monomials of a given degree in a multivariable polynomial ring?

For example I want to input x,y,3 and get

x^3, x^2y, xy^2, y^3.

I think I could code it myself with not too much work, but it seems like something that might already have a nice method.

I created a minimal example in the file bad.py

from sage.all import *

j = 0
m = matrix(3,3)
m.insert_row(j, [1,1,1])

Then from sage:

sage: load bad.py
TypeError: Cannot convert int to sage.rings.integer.Integer

I think I can see an easy workaround, I can wrap all the 1's in Integer() (or change the name of the file to .sage so the preparser does it), but why is that necessary? Is this a bug? Why would sage not be able to convert int to Integer? Isn't that a pretty obvious conversion?

I am working on a project to do some computations for a specialized theory. Currently, we have several files that define different objects that have various dependencies on each other. Currently, I have a file named "attachall.sage" that looks like

attach "poly.sage"

attach "util2.sage"

attach "quasihomogeneous.sage"

attach "FJRW.sage"

attach "algebra.sage"

etc. Then when I want to do some computations, I do

sage: load attachall.sage

sage: #do stuff with the objects

It works fine, I guess, but doesn't seem particularly clean-- it seems like there should be a preferred way to do this. Should I use python's import? But then I would have to re-preparse every time I changed the source, and have potentially annoying bugs if someone forgot to re-preparse after changing a file. Or should I look into making a spkg? I don't really know a lot about that and I'd like to keep it simple.

Eventually we'd like to be able to share this code with other groups.

Does anyone have any thoughts?

sage.misc.misc.inject_variable might be your friend.

Thank you! It is my friend!

Here is a minimal example of the problem I am running into. I have a file "MyClass.py":

class MyClass(object):
    def __init__(self,subscript):
        self.subscript = subscript

    def __repr__(self):
        return "MyClass " + str(self.subscript)

def make_MyClass(n):
    """
    Creates n MyClass instances and assigns them to to variables A0, ..., A(n-1).

    Examples::

        sage: make_MyClass(3)
        sage: A0
        MyClass 0
        sage: A2
        MyClass 2
        sage: A1.subscript
        1
    """
    for i in range(n):
        globals()["A" + str(i)] = MyClass(i)

If I doctest it, I get NameError: name 'A0' is not defined, but if I just load the file and type in the commands, it works how I want it to. It must be something about how globals() interacts with doctest.

I know it is possible to make this work, because for example the function var does something like this. I tried looking at the var.pyx source, but it looks like they are doing the same thing as me. (There is a comment about globals() being the reason that it had to be Cython. I tried making the example above a pyx, but that didn't seem to help.)