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:


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 (/usr/local/sage-8/src/build/cythonized/sage/misc/misc_c.c:1596)()
    ---> 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)
    sage: X(j).maxima_methods().product(j,1,p)

(Note : similar nonsense also happens with sums :

sage: X(j).maxima_methods().sum(j,1,p)


  • 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)

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