Jeffrey Arnold

Use twitter-text to extract hashtags, mentions, and URLs

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Currently the tokenizer has it's own regex's for hashtags, mentions, and URLs (and there's a comment about what the best URL pattern is). Twitter maintains a java library [twitter-text](https://github.com/twitter/twitter-text) that...

Primary key of `nycflights13::flights` and `nycflights13::weather`

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## Primary key of `flights` In the chapter on Relational Data, section [Keys](https://r4ds.had.co.nz/relational-data.html#keys), the text describes the `flights` table as having no primary key. > Sometimes a table doesn’t have...

The question: "Why is TRUE not a parameter to rescale01()?" is awkward. Does this mean, why is `na.rm = TRUE` instead of `na.rm = na.rm` where `na.rm` is a parameter?

Problems with Exercise 21.5.3

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The question text is: > Rewrite map(x, function(df) lm(mpg ~ wt, data = df)) to eliminate the anonymous function. The code is confusing. What is this code supposed to represent?...

The question reads: > Read the documentation for `apply()`. In the 2d case, what two for loops does it generalize? The first time, I read "2d case" as the "2nd...

It looks like there are already tidiers in the **broom** package for rstanarm and stanfit objects, but I didn't see any for loo objects. So I wrote some. I could...

Respond to hypothes.is annotation [yZfiPsE-Eeq9MHPUawXdSA](https://hypothes.is/a/yZfiPsE-Eeq9MHPUawXdSA) on https://jrnold.github.io/r4ds-exercise-solutions/relational-data.html (user: acct:[email protected], created: 2020-07-08T17:16:40.167063+00:00, updated: 2020-07-08T17:16:40.167063+00:00) > used Link: https://hyp.is/yZfiPsE-Eeq9MHPUawXdSA/jrnold.github.io/r4ds-exercise-solutions/relational-data.html

Respond to hypothes.is annotation [UWdu0MCrEeqwUtuHtJ-QoQ](https://hypothes.is/a/UWdu0MCrEeqwUtuHtJ-QoQ) on https://jrnold.github.io/r4ds-exercise-solutions/relational-data.html (user: acct:[email protected], created: 2020-07-07T23:41:02.441740+00:00, updated: 2020-07-07T23:41:02.441740+00:00) > some of the exercises for this subsection a little premature...for some readers (like me) it is...

Respond to hypothes.is annotation [ppRnxsCeEeqycqcWi8jXhg](https://hypothes.is/a/ppRnxsCeEeqycqcWi8jXhg) on https://jrnold.github.io/r4ds-exercise-solutions/tidy-data.html (user: acct:[email protected], created: 2020-07-07T22:10:21.956819+00:00, updated: 2020-07-07T22:10:21.956819+00:00) > another reason why I bring this up is that there are no cases where "key" is...

Respond to hypothes.is annotation [VYvGHMCeEeqI-i_miuQj_Q](https://hypothes.is/a/VYvGHMCeEeqI-i_miuQj_Q) on https://jrnold.github.io/r4ds-exercise-solutions/tidy-data.html (user: acct:[email protected], created: 2020-07-07T22:08:06.040853+00:00, updated: 2020-07-07T22:08:06.040853+00:00) > perhaps you mean "only some observations/rows to be missing"? Link: https://hyp.is/OqvfbMCeEeqrRDcyAXIMJA/jrnold.github.io/r4ds-exercise-solutions/tidy-data.html