Better docs for Subs. #2649
Better docs for Subs. #2649
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| The substitution is literal replacement of old arguments with new one | ||
| and it may not reflect the limiting behaviour of the expression. | ||
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| >>> (x**3 - 3*x).subs({x:oo}) |
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space after colon. or just subs(x, oo)?
Also, may be you can include limit result as well? See, for example, a demo for simultaneous=True.
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anyway, +1 |
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Move the example down. You've injected it in the middle of a discussion about the difference between subs and xreplace. |
| See Also | ||
| ======== | ||
| replace: replacement capable of doing wildcard-like matching, | ||
| parsing of match, and conditional replacements | ||
| xreplace: exact node replacement in expr tree; also capable of | ||
| using matching rules | ||
| evalf: evaluate the given formula to a given accuracy of digits |
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..and note that evalf calculates to a desired level of precision.
On Thu, Dec 5, 2013 at 8:19 AM, Sergey B Kirpichev <notifications@github.com
wrote:
In sympy/core/basic.py:
See Also ======== replace: replacement capable of doing wildcard-like matching, parsing of match, and conditional replacements xreplace: exact node replacement in expr tree; also capable of using matching rules
evalf: evaluate the given formula to a given accuracy of digitsWhy this?
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Reply to this email directly or view it on GitHubhttps://github.com//pull/2649/files#r8129547
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@skirpichev I did this because I thought people might try to substitute the variable with a constant to evaluate the expression. My unnecessary pull request [1] was also in some ways a result of confusion between evalf and subs. So I think adding evalf in the See Also section might serve as a good pointer.
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ok, if there is no objection against, I'll merge this in 24h. @hargup, I think it's good to give a bit more verbose and descriptive commit message. |
- Added examples to resolve confusion regarding the result of subs and the limiting value of the expression at that point - Added examples to clearly show the difference between substitution and numerical evaluation. - Added `evalf` in the `See Also` of `Subs` documentation section.
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@skirpichev Thanks, I have updated the commit message and the pull request description. |
evalfin theSee AlsoofSubsdocumentation section.