Wrap-Up

class: title-slide, center

# Wrap-Up

## Tidy Data Science with the Tidyverse and Tidymodels

### W. Jake Thompson

#### [https://tidyds-2021.wjakethompson.com](https://tidyds-2021.wjakethompson.com) &#183; [https://bit.ly/tidyds-2021](https://bit.ly/tidyds-2021)

.footer-license[*Tidy Data Science with the Tidyverse and Tidymodels* is licensed under a [Creative Commons Attribution 4.0 International License](https://creativecommons.org/licenses/by/4.0/).]

<div style = "position:fixed; visibility: hidden">
  `$$\require{color}\definecolor{blue}{rgb}{0, 0.623529411764706, 0.717647058823529}$$`
  `$$\require{color}\definecolor{light_blue}{rgb}{0.0392156862745098, 0.870588235294118, 1}$$`
  `$$\require{color}\definecolor{yellow}{rgb}{0.996078431372549, 0.843137254901961, 0.4}$$`
  `$$\require{color}\definecolor{dark_yellow}{rgb}{0.635294117647059, 0.47843137254902, 0.00392156862745098}$$`
  `$$\require{color}\definecolor{pink}{rgb}{0.796078431372549, 0.16078431372549, 0.482352941176471}$$`
  `$$\require{color}\definecolor{light_pink}{rgb}{1, 0.552941176470588, 0.776470588235294}$$`
  `$$\require{color}\definecolor{grey}{rgb}{0.411764705882353, 0.403921568627451, 0.450980392156863}$$`
</div>
  
<script type="text/x-mathjax-config">
  MathJax.Hub.Config({
    TeX: {
      Macros: {
        blue: ["{\\color{blue}{#1}}", 1],
        light_blue: ["{\\color{light_blue}{#1}}", 1],
        yellow: ["{\\color{yellow}{#1}}", 1],
        dark_yellow: ["{\\color{dark_yellow}{#1}}", 1],
        pink: ["{\\color{pink}{#1}}", 1],
        light_pink: ["{\\color{light_pink}{#1}}", 1],
        grey: ["{\\color{grey}{#1}}", 1]
      },
      loader: {load: ['[tex]/color']},
      tex: {packages: {'[+]': ['color']}}
    }
  });
</script>

---
background-image: url(images/wrap-up/applied-ds.png)
background-position: center 60%
background-size: 85%

# .nobold[(Applied)] Data Science

---
background-image: url(images/wrap-up/applied-ds-hex.png)
background-position: center 60%
background-size: 85%

# .nobold[(Applied)] Data Science

---
background-image: url(images/wrap-up/tm.png)
background-size: cover

---
background-image: url(images/wrap-up/tm-hex.png)
background-size: cover

---
background-image: url(images/wrap-up/hex-wall.png)
background-size: contain

---
background-image: url(images/wrap-up/hex-wall-reprex.png)
background-size: contain

---
<div class="hex-book">
  <a href="https://reprex.tidyverse.org/">
    <img class="hex" src="images/hex/reprex.png">
  </a>
  <a href="https://r4ds.had.co.nz/introduction.html#getting-help-and-learning-more">
    <img class="book" src="images/books/r4ds-reprex.png">
  </a>
</div>

---
# Please help!

.center[
![](https://media.giphy.com/media/fdLR6LGwAiVNhGQNvf/giphy.gif)
]

.center.big[
Create a .display[repr]oducible .display[ex]ample (.display[reprex])
]

---
# reprex

**Goal**: create the *simplest example possible* to illustrate the problem/question, that anyone can run on their own machine

* Can't use data stored on your computer (others won't have that)

* Can't assume options or settings are the same across computers

.display[reprex] to the rescue!

---
# Example

**Question**: How do I sort by a sum and then all component columns?

.center[
![](https://media.giphy.com/media/t6WvtUluR8V2NSxLlk/giphy.gif)
]

---
# My use case

.pull-left[
.small[

```r
dat3
#> # A tibble: 50 x 4
#>    student_id skill_1 skill_2 skill_3
#>         <int>   <int>   <int>   <int>
#>  1       3462       0       0       1
#>  2       3510       1       1       1
#>  3       9717       1       0       1
#>  4       3985       0       1       0
#>  5       2841       1       0       1
#>  6       4370       1       0       1
#>  7       5760       0       0       1
#>  8       7745       0       0       0
#>  9       3756       0       0       1
#> 10       6106       1       0       1
#> # … with 40 more rows
```
]
]

.pull-right[
.small[

```r
dat4
#> # A tibble: 50 x 5
#>    student_id skill_1 skill_2 skill_3 skill_4
#>         <int>   <int>   <int>   <int>   <int>
#>  1       1472       0       1       1       1
#>  2       7097       0       1       0       1
#>  3       2148       0       1       1       0
#>  4       3036       0       1       0       1
#>  5       3312       1       1       1       1
#>  6       8740       0       1       0       0
#>  7       9649       0       1       1       1
#>  8       2077       0       0       0       1
#>  9       6014       0       1       0       0
#> 10       6657       1       0       0       1
#> # … with 40 more rows
```
]
]

???

I have some data that shows which of 3 skills each student has mastered. I want to sort the data by the total number of skills mastered, and then by each skill. But the number of skills can change. How can I write a solution that will work for any number of skills?

---
# Include data

**Question**: How do I sort a data frame by total skills and then each component skill?

.pull-left[
.smallish[

.pull-right[
![](https://media.giphy.com/media/1QhmDy91F9veMRLpvK/giphy.gif)
]

???

You can't do anything with this. You don't have `dat3` on your computer, and you can't copy/paste this df into an R object. Would have to build it by hand.

---
# Include .display[repr]oducible .display[ex]ample data

```r
library(tidyverse)

ex_data <- tibble(stu     = c(1, 2, 3, 4, 5),
                  skill_1 = c(0, 0, 1, 1, 1),
                  skill_2 = c(1, 1, 0, 0, 0),
                  skill_3 = c(0, 1, 0, 1, 1))

ex_data
#> # A tibble: 5 x 4
#>     stu skill_1 skill_2 skill_3
#>   <dbl>   <dbl>   <dbl>   <dbl>
#> 1     1       0       1       0
#> 2     2       0       1       1
#> 3     3       1       0       0
#> 4     4       1       0       1
#> 5     5       1       0       1
```

---
# Asking questions

**Bad**: How do I sort by a sum and then all component columns?

**Better**: How can I sort a data frame by total skills and then each component skill?

**Best**: Provide an example of what you want (including the **better** question), and solutions you've tried.

---

```r
# What I want:
ex_data %>%
  mutate(total = skill_1 + skill_2 + skill_3) %>%
  arrange(total, desc(skill_1, skill_2, skill_3))
#> # A tibble: 5 x 5
#>     stu skill_1 skill_2 skill_3 total
#>   <dbl>   <dbl>   <dbl>   <dbl> <dbl>
#> 1     3       1       0       0     1
#> 2     1       0       1       0     1
#> 3     4       1       0       1     2
#> 4     5       1       0       1     2
#> 5     2       0       1       1     2
```

But without specifying each skill individually, because the number of skills may change.

---

```r
# What I've tried

ex_data %>%
  rowwise() %>%
  mutate(total = sum(c_across(starts_with("skill")))) %>%
  ungroup() %>%
  arrange(total, desc(starts_with("skill")))
#> Error: arrange() failed at implicit mutate() step. 
#> * Problem with `mutate()` input `..2`.
#> x `starts_with()` must be used within a *selecting* function.
#> ℹ See <https://tidyselect.r-lib.org/reference/faq-selection-context.html>.
#> ℹ Input `..2` is `starts_with("skill")`.
```

---
# Anatomy of a good question

* __*Brief*__ description of what you're doing

* Reproducible data

* What you've tried

* What you've gotten

* What you want to get

---
# Anatomy of a good question

.fade[
* __*Brief*__ description of what you're doing
]

* Reproducible data

* What you've tried

* What you've gotten

.fade[
* What you want to get
]

???

reprex makes this part easier

---
# `reprex()`