Opened 4 years ago
Last modified 4 years ago
#22914 closed defect
Symbolic products are currently broken. — at Initial Version
Reported by: | charpent | Owned by: | |
---|---|---|---|
Priority: | major | Milestone: | sage-duplicate/invalid/wontfix |
Component: | symbolics | Keywords: | symbolics |
Cc: | rws | Merged in: | |
Authors: | Reviewers: | ||
Report Upstream: | N/A | Work issues: | |
Branch: | Commit: | ||
Dependencies: | Stopgaps: |
Description
The symbolic product is currently broken in Sage :
- It cannot be created in Sage :
sage: var("j,p", domain="integer") sage: X,Y=function("X,Y") sage: prod(X(j),j,1,p) --------------------------------------------------------------------------- TypeError Traceback (most recent call last) <ipython-input-5-85e69544cbe9> in <module>() ----> 1 prod(X(j),j,Integer(1),p) /usr/local/sage-8/src/sage/misc/misc_c.pyx in sage.misc.misc_c.prod (/usr/local/sage-8/src/build/cythonized/sage/misc/misc_c.c:1596)() 69 70 ---> 71 def prod(x, z=None, Py_ssize_t recursion_cutoff=5): 72 """ 73 Return the product of the elements in the list x. TypeError: prod() takes at most 3 positional arguments (4 given) sage: product(X(j),j,1,p) --------------------------------------------------------------------------- NameError Traceback (most recent call last) <ipython-input-6-4d04d74c7489> in <module>() ----> 1 product(X(j),j,Integer(1),p) NameError: name 'product' is not defined
- Creatnig it it by casting a Maxima expression via the library interface gives nonsense :
sage: X(j).maxima_methods().prod(j,1,p) X(j)^p sage: X(j).maxima_methods().product(j,1,p) X(j)^p
(Note : similar nonsense also happens with sums :
sage: X(j).maxima_methods().sum(j,1,p) p*X(j)
)
- But something (what ?) can be created via the Maxima
pexpect
interface :sage: maxima("prod(X(j),j,1,p)").sage().log().log_expand() sum(log(X(j)), j, 1, p)
Note: See
TracTickets for help on using
tickets.