ASKSAGE: Sage Q&A Forum - RSS feedhttps://ask.sagemath.org/questions/Q&A Forum for SageenCopyright Sage, 2010. Some rights reserved under creative commons license.Wed, 17 Apr 2019 23:57:20 +0200Computations in the ring of integers of a number fieldhttps://ask.sagemath.org/question/46252/computations-in-the-ring-of-integers-of-a-number-field/Suppose I have some number field $K$, with its ring of integers $O_K$ = K.ring_of_integers(). If $I$ is an ideal of $O_K$ (or, if $I$ is a fractional ideal of $K$), I'd like to be able to compute with the ring $O_K/I$. For example, I'd like to be able to ask how big that ring is.
K.<omega> = NumberField(x^2+x+1)
OK = K.ring_of_integers()
R.<a,b> = OK.quo(OK.ideal(9))
R.cardinality()
gives a NotImplementedError. (Even though cardinality shows up as one of the supported methods if I type R.??).
Or, again for example, I'd like to be able to determine the ring structure of $R$, or the structure of its group of units, but none of these methods seem to actually be supported.
The type of R is sage.rings.quotient_ring.QuotientRing_generic_with_category.
What am I missing?rogerlWed, 17 Apr 2019 23:57:20 +0200https://ask.sagemath.org/question/46252/