This issue is good for someone with a mathematical/statistical background, who is comfortable with basic LaTex-style math markup.
In Bug 18677, Jorgen Harmse (JH) proposes improvements to the documentation files. This issue will iterate on these suggestions and create a patch file for the proposed changes.
Suggestion to replace $\ln \Gamma$ with lgamma in the formula for digamma (where lgamma computes the natural logarithm of the absolute value of the gamma function). I think this change can be skipped - the definition with $\ln \Gamma$ is used widely (e.g. several refs on Wikipedia, including Abramowitz and Stegun) and as $\ln \Gamma$ is defined for negative values (via complex numbers) I don't see an issue here (see e.g. this discussion on mathematics Stack Exchange).
Changes to ?is.numeric
The issue here is some surprise that is.numeric returns FALSE for complex numbers. This is as documented, e.g.
Methods for is.numeric should only return true if the base type of the class is double or integer
I suggest extending the part
there are methods for classes "Date", "POSIXt" and "difftime" (all of which return false)
Using the GitHub mirror, as documented in the R Dev Guide of the R sources. Rather than editing the file in the GitHub browser interface, I would make local copies of the files and edit there. When you have final versions, then you can follow the workflow given in the R Dev Guide to create a patch.
In both cases:
Refer to Writing R Extensions to ensure you are using correct markup (it is LaTeX-like not markdown-like!)
This issue is good for someone with a mathematical/statistical background, who is comfortable with basic LaTex-style math markup.
In Bug 18677, Jorgen Harmse (JH) proposes improvements to the documentation files. This issue will iterate on these suggestions and create a patch file for the proposed changes.
Changes to ?gamma
lgamma
in the formula fordigamma
(wherelgamma
computes the natural logarithm of the absolute value of the gamma function). I think this change can be skipped - the definition with $\ln \Gamma$ is used widely (e.g. several refs on Wikipedia, including Abramowitz and Stegun) and as $\ln \Gamma$ is defined for negative values (via complex numbers) I don't see an issue here (see e.g. this discussion on mathematics Stack Exchange).Changes to ?is.numeric
The issue here is some surprise that
is.numeric
returns FALSE for complex numbers. This is as documented, e.g.I suggest extending the part
to include
"complex"
.How to make the changes
I suggest editing the help files (src/library/stats/man/GammaDist.Rd and src/library/base/man/numeric.Rd in one of two ways:
In both cases:
tools::checkRd()