Opened 12 years ago

Closed 9 years ago

## #10955 closed task (fixed)

# Get Maxima to easily accept flag values

Reported by: | Karl-Dieter Crisman | Owned by: | Burcin Erocal |
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Priority: | trivial | Milestone: | sage-6.3 |

Component: | calculus | Keywords: | maxima, calculus, flag, radexpand |

Cc: | Robert Marik, Burcin Erocal, Nils Bruin, Jason Grout, David Joyner | Merged in: | |

Authors: | Peter Bruin | Reviewers: | Nils Bruin, Karl-Dieter Crisman |

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

Branch: | b94b48a (Commits, GitHub, GitLab) | Commit: | b94b48a873b29617f5562f18ffd1a61d67b1a7a6 |

Dependencies: | Stopgaps: |

### Description

Maxima relatively recently decided that 1/sqrt(x) is not sqrt(1/x), for good reasons (1/sqrt(-1)=-i but sqrt(1/-1)=i in usual discussion). So for the following integral, they note that it depends on how you input it:

sage: integrate(sqrt(1/x^2+x),x) integrate(sqrt(x + 1/x^2), x) sage: integrate(1/sqrt(x^2+x),x) log(2*x + 2*sqrt(x^2 + x) + 1)

Fine. Then they suggest using the flag `radexpand:all`

to make the first one behave. But I can't figure out how to get it to evaluate.

sage: sage.calculus.calculus.maxima('radexpand:all') all sage: integrate(sqrt(1/x^2+x),x) integrate(sqrt(x + 1/x^2), x)

Trying maxima.eval only changes that I get 'all' instead of all. We should make this work, since this is the *calculus* instance of Sage!

### Change History (5)

### comment:1 Changed 9 years ago by

### comment:2 Changed 9 years ago by

Authors: | → Peter Bruin |
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Branch: | → u/pbruin/10955-maxima_radexpand |

Commit: | → b94b48a873b29617f5562f18ffd1a61d67b1a7a6 |

Milestone: | → sage-6.3 |

Priority: | minor → trivial |

Status: | new → needs_review |

Type: | defect → task |

Works for me too; here is a doctest.

### comment:3 Changed 9 years ago by

Reviewers: | → Nils Bruin, Karl-Dieter Crisman, Michael Orlitzky |
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Status: | needs_review → positive_review |

As far as I can tell this is fine. I have no idea why this didn't work before. Passes tests, does right thing.

Wow, I am just now noticing that the suggestion made earlier was pretty bogus.

sage: integrate(1/sqrt(x^2+x),x) log(2*x + 2*sqrt(x^2 + x) + 1)

Totally not the same thing as `sqrt(1/x^2+x)`

! Should have been

sage: integrate(1/sqrt(x^2+x),x) log(2*x + 2*sqrt(x^2 + x) + 1) sage: integrate(sqrt(1/(x^2+x)),x) log(sqrt(x + 1)/sqrt(x) + 1) - log(sqrt(x + 1)/sqrt(x) - 1)

which also happens to be affected by `radexpand:all`

.

### comment:4 Changed 9 years ago by

Reviewers: | Nils Bruin, Karl-Dieter Crisman, Michael Orlitzky → Nils Bruin, Karl-Dieter Crisman |
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### comment:5 Changed 9 years ago by

Branch: | u/pbruin/10955-maxima_radexpand → b94b48a873b29617f5562f18ffd1a61d67b1a7a6 |
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Resolution: | → fixed |

Status: | positive_review → closed |

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Works for me on some flavour of 5.13.beta0

I didn't check if the answer makes sense, but at least setting the flag has effect.