Opened 10 years ago

Last modified 4 years ago

## #9130 closed enhancement

# Access to beta function — at Initial Version

Reported by: | kcrisman | Owned by: | burcin |
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Priority: | major | Milestone: | sage-5.0 |

Component: | symbolics | Keywords: | special function, pynac, sd35.5 Cernay2012 |

Cc: | benjaminfjones | Merged in: | |

Authors: | Reviewers: | ||

Report Upstream: | N/A | Work issues: | |

Branch: | Commit: | ||

Dependencies: | Stopgaps: |

### Description

Although Maxima has the beta function, Sage doesn't:

sage: a, b, c = var('a b c') sage: assume(a > 0) sage: assume(b > 0) sage: x = var('x') sage: beta_dist = x**(a-1) * (1 - x)**(b-1) sage: c = integral(beta_dist, x, 0, 1) sage: c beta(a, b) sage: c(a=.5,b=.5) beta(0.500000000000000, 0.500000000000000) sage: c(a=.5,b=.5).n() --------------------------------------------------------------------------- TypeError Traceback (most recent call last) /Users/karl-dietercrisman/<ipython console> in <module>() /Users/karl-dietercrisman/Desktop/sage-4.4.2/local/lib/python2.6/site-packages/sage/symbolic/expression.so in sage.symbolic.expression.Expression.n (sage/symbolic/expression.cpp:17042)() TypeError: cannot evaluate symbolic expression numerically

This *is* is Ginac, though, and there is even room for defining it in symbolic/expression.pyx . It probably is also included in some of our other libraries, as a standard special function.

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