Opened 3 years ago

Closed 3 years ago

#20297 closed defect (fixed)

ECL crash with Hermite polynomials

Reported by: rws Owned by:
Priority: major Milestone: sage-duplicate/invalid/wontfix
Component: symbolics Keywords:
Cc: Merged in:
Authors: Reviewers:
Report Upstream: N/A Work issues:
Branch: Commit:
Dependencies: #20312 Stopgaps:

Description (last modified by rws) 

sage: %time _=hermite(10000,x)
---------------------------------------------------------------------------
RuntimeError                              Traceback (most recent call last)
RuntimeError: ECL says: Memory limit reached. Please jump to an outer pointer, quit program and enlarge the
memory limits before executing the program again.

There is no reason for this because coefficients can be computed directly using big integers: 

sage: %time _= [factorial(10000)/(factorial(k)*factorial(10000-2*k)) for k in range(1,5000)]
CPU times: user 4.33 s, sys: 24 ms, total: 4.35 s
Wall time: 4.32 s

A Pynac prototype is about 50x faster than Maxima for expression creation and creates H_10000 in 670ms.

Change History (5)

comment:1 Changed 3 years ago by rws

  • Description modified (diff)

comment:2 Changed 3 years ago by rws

  • Dependencies set to #20312

comment:3 Changed 3 years ago by rws

  • Milestone changed from sage-7.2 to sage-duplicate/invalid/wontfix
  • Status changed from new to needs_review

Fixed in #20312.

comment:4 Changed 3 years ago by rws

  • Status changed from needs_review to positive_review

comment:5 Changed 3 years ago by vbraun

  • Resolution set to fixed
  • Status changed from positive_review to closed
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