cleanup

- fix markdown
- fix links
- fix html

datetimes.Rmd

@@ -440,5 +440,3 @@ as.Date("2016-02-29") + years(1)
 ## Time Zones {#time-zones .r4ds-section}
 
 `r no_exercises()`
-
-<div><!-- open unclosed div -->

index.Rmd

@@ -113,17 +113,15 @@ hypothesis_contribs <- function() {
 These solutions have benefited from many contributors.
 A special thanks to:
 
--  Garrett Grolemund and Hadley Wickham for writing the truly fantastic *R for Data Science* , without which these solutions would not exist---literally.
-
--  [\@dongzhuoer](https://github.com/dongzhuoer) for a careful reading of the book and noticing numerous issues and proposing fixes.
+-   Garrett Grolemund and Hadley Wickham for writing the truly fantastic *R for Data Science* , without which these solutions would not exist---literally.
 
+-   [\@dongzhuoer](https://github.com/dongzhuoer) for a careful reading of the book and noticing numerous issues and proposing fixes.
 
 Thank you to all of those who contributed issues or pull-requests on
 [GitHub](https://github.com/jrnold/r4ds-exercise-solutions/graphs/contributors) 
 (in alphabetical order): `r github_contribs()`
 Thank you to all of you who contributed annotations on [hypothes.is](https://hypothes.is/search?q=url%3Ajrnold.github.io%2Fr4ds-exercise-solutions%2F*) (in alphabetical order): `r hypothesis_contribs()`.
 
-
-## 
+## License {-}
 
 This work is licensed under a <a rel="license" href="http://creativecommons.org/licenses/by/4.0/">Creative Commons Attribution 4.0 International License</a>

intro.Rmd

@@ -18,7 +18,7 @@ If exercises depend on code in a section of *R for Data Science* it is either pr
 If a package is used infrequently in solutions it may not be loaded, and functions using it will be called using the package name followed by two colons, as in `dplyr::mutate()` (see the *R for Data Science* [Introduction](http://r4ds.had.co.nz/introduction.html#running-r-code)).
 The double colon may also be used to be explicit about the package from which a function comes.
 
-## Prerequisites
+## Prerequisites {-}
 
 This book is a complement to, not a substitute of, [R for Data Science]().
 It only provides the exercise solutions for it. 
@@ -58,5 +58,3 @@ This book was built with these R packages.
 ```{r colonophon}
 devtools::session_info("r4ds.exercise.solutions")
 ```
-
-<div><!-- open unclosed div -->

iteration.Rmd

@@ -669,7 +669,7 @@ Write code that uses one of the map functions to:
     ```
     Since a single call of `rnorm()` returns a numeric vector with a length greater
     than one we cannot use `map_dbl`, which requires the function to return a numeric
-    vector that is only length one (see [Exercise 21.5.4](exercise-21.5.4)). 
+    vector that is only length one (see [Exercise 21.5.4](#exercise-21.5.4)). 
     The map functions pass any additional arguments to the function being called.
 
 </div>
@@ -934,5 +934,3 @@ The `sapply()` function tries to be helpful by simplifying the results, but this
 It is okay to use the `sapply()` function interactively, but avoid programming with it.
 
 </div>
-
-<div><!-- open unclosed div -->

many-models.Rmd

@@ -270,5 +270,3 @@ Lists are not atomic since they can contain other lists and other vectors.
 ## Making tidy data with broom {#making-tidy-data-with-broom .r4ds-section}
 
 `r no_exercises()`
-
-<div><!-- open unclosed div -->

rmarkdown-workflow.Rmd

@@ -1,5 +1,3 @@
 # R Markdown workflow {#r-markdown-workflow .r4ds-section}
 
 `r no_exercises()`
-
-<div><!-- close unopened div -->

rmarkdown.Rmd

@@ -245,7 +245,7 @@ Check that you can run it, then add text after the frequency polygon that descri
 
 <div class="answer">
 
-The following R markdown document answers this question as well as exercises [Exercise 27.4.1](exercise-27.4.1), [Exercise 27.4.2](exercise-27.4.2), and [Exercise 27.4.3](exercise-27.4.3).
+The following R markdown document answers this question as well as exercises [Exercise 27.4.1](#exercise-27.4.1), [Exercise 27.4.2](#exercise-27.4.2), and [Exercise 27.4.3](#exercise-27.4.3).
 
 ```{r diamond-sizes,echo=FALSE,comment='',purl=FALSE}
 cat(readr::read_file(here::here("rmarkdown", "diamond-sizes.Rmd")))
@@ -264,7 +264,7 @@ Assume you’re writing a report for someone who doesn’t know R, and instead o
 
 <div class="answer">
 
-See the answer to [Exercise 27.3.3](exercise-27.3.3).
+See the answer to [Exercise 27.3.3](#exercise-27.3.3).
 
 </div>
 
@@ -277,7 +277,7 @@ Add a section that describes the largest 20 diamonds, including a table that dis
 
 <div class="answer">
 
-See the answer to [Exercise 27.3.3](exercise-27.3.3).
+See the answer to [Exercise 27.3.3](#exercise-27.3.3).
 I use `arrange()` and `slice()` to select the largest twenty diamonds, and
 `knitr::kable()` to produce a formatted table.
 
@@ -292,7 +292,7 @@ Also include the percentage of diamonds that are larger than 2.5 carats.
 
 <div class="answer">
 
-See the answer to [Exercise 27.3.3](exercise-27.3.3).
+See the answer to [Exercise 27.3.3](#exercise-27.3.3).
 
 I moved the computation of the number larger and percent of diamonds larger than 2.5 carats into a code chunk.
 I find that it is best to keep inline R expressions simple, usually consisting of an object and a formatting function.

visualize.Rmd

@@ -347,7 +347,7 @@ Aesthetics can also be mapped to expressions like `displ < 5`.
 The `ggplot()` function behaves as if a temporary variable was added to the data with with values equal to the result of the expression.
 In this case, the result of `displ < 5` is a logical variable which takes values of `TRUE` or `FALSE`.
 
-This also explains why, in [Exercise 3.3.1](exercise-3.3.1), the expression `colour = "blue"` created a categorical variable with only one category: "blue".
+This also explains why, in [Exercise 3.3.1](#exercise-3.3.1), the expression `colour = "blue"` created a categorical variable with only one category: "blue".
 
 </div>
 

workflow-projects.Rmd

@@ -1,5 +1,3 @@
 # Workflow: projects {#workflow-projects .r4ds-section}
 
 `r no_exercises()`
-
-<div><!-- open unclosed div -->