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tidyverse-2023.qmd
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---
title: "what's new<br>in the tidyverse<br>in 2023?"
subtitle: "[🔗 mine.quarto.pub/tidyverse-2023](https://mine.quarto.pub/tidyverse-2023) <br><br> [💻 github.com/mine-cetinkaya-rundel/tidyverse-2023](https://github.com/mine-cetinkaya-rundel/tidyverse-2023)"
institute: "duke university + posit"
author: "dr. mine çetinkaya-rundel"
date: "2023-05-30"
title-slide-attributes:
data-background-image: images/tidyverse-hexes.png
logo: "images/tidyverse.png"
format:
revealjs:
theme: theme.scss
transition: fade
slide-number: true
chalkboard: true
background-transition: fade
height: 900
width: 1600
fontcolor: "#262d36"
highlight-style: a11y-dark
multiplex: true
footer: "[🔗 mine.quarto.pub/tidyverse-2023](https://mine.quarto.pub/tidyverse-2023)"
include-after-body: clean_title.html
code-link: true
editor: visual
execute:
freeze: auto
echo: true
warning: true
editor_options:
chunk_output_type: console
---
```{r}
#| label: setup
#| include: false
# set width of code output
options(width = 65)
# set plot defaults
ggplot2::theme_set(ggplot2::theme_gray(base_size = 14))
# set figure parameters for knitr
knitr::opts_chunk$set(
out.width = "80%",
fig.width = 8, # 7" width
fig.asp = 0.618, # the golden ratio
fig.retina = 3, # dpi multiplier for displaying HTML output on retina
fig.align = "center", # center align figures
dpi = 300 # higher dpi, sharper image
)
options(
dplyr.print_min = 6,
dplyr.print_max = 6
)
```
# principles of the tidyverse
## tidyverse
::: columns
::: {.column width="80%"}
meta R package that loads nine core packages when invoked and also bundles numerous other packages that share a design philosophy, common grammar, and data structures
::: {.fragment fragment-index="1"}
```{r}
#| warning: false
library(tidyverse)
```
```
── Attaching core tidyverse packages ──────── tidyverse 2.0.0 ──
✔ dplyr 1.1.2 ✔ readr 2.1.4
✔ forcats 1.0.0 ✔ stringr 1.5.0
✔ ggplot2 3.4.2 ✔ tibble 3.2.1
✔ lubridate 1.9.2 ✔ tidyr 1.3.0
✔ purrr 1.0.1
── Conflicts ────────────────────────── tidyverse_conflicts() ──
✖ dplyr::filter() masks stats::filter()
✖ dplyr::lag() masks stats::lag()
ℹ Use the conflicted package to force all conflicts to become errors
```
:::
:::
::: {.column width="20%"}
![](images/tidyverse.png){fig-alt="Tidyverse hex icon" fig-align="center"}
:::
:::
## tidyverse for data science
::: {.fragment fragment-index="2"}
![](images/data-science.png){fig-alt="Data science cycle: import, tidy, transform, visualize, model, communicate. Packages readr and tibble are for import. Packages tidyr and purr for tidy and transform. Packages dplyr, stringr, forcats, and lubridate are for transform. Package ggplot2 is for visualize." fig-align="center"}
:::
## setup: `penguins`
```{r}
library(palmerpenguins)
penguins
```
::: aside
:::
## a typical tidyverse pipeline
```{r}
#| label: typical-pipeline
#| fig-asp: 0.4
#| fig-alt: |
#| Dodged bar plot of average body masses of penguins by species and sex.
#| Gentoo penguins weigh more, on average, than Adelies and Chinstraps,
#| and within each species males weigh more, on average, than females.
penguins |>
drop_na(sex, body_mass_g) |>
group_by(species, sex) |>
summarize(mean_bw = mean(body_mass_g), .groups = "drop") |>
ggplot(aes(x = species, y = mean_bw, fill = sex)) +
geom_col(position = "dodge")
```
## a typical tidyverse workflow
```{r}
#| code-line-numbers: "|1|1-2|1-3"
penguins |>
group_by(species, sex) |>
summarize(mean_bw = mean(body_mass_g))
```
## a typical tidyverse workflow
```{r}
#| code-line-numbers: "2|1-4"
penguins |>
drop_na(sex, body_mass_g) |>
group_by(species, sex) |>
summarize(mean_bw = mean(body_mass_g))
```
## a typical tidyverse workflow
```{r}
#| code-line-numbers: "4|1-4"
penguins |>
drop_na(sex, body_mass_g) |>
group_by(species, sex) |>
summarize(mean_bw = mean(body_mass_g), .groups = "drop")
```
## a typical tidyverse workflow
```{r}
#| fig-asp: 0.4
#| code-line-numbers: "5-6|1-6"
#| fig-alt: |
#| Dodged bar plot of average body masses of penguins by species and sex.
#| Gentoo penguins weigh more, on average, than Adelies and Chinstraps,
#| and within each species males weigh more, on average, than females.
penguins |>
drop_na(sex, body_mass_g) |>
group_by(species, sex) |>
summarize(mean_bw = mean(body_mass_g), .groups = "drop") |>
ggplot(aes(x = species, y = mean_bw, fill = sex)) +
geom_col()
```
## a typical tidyverse workflow
```{r}
#| ref.label: typical-pipeline
#| fig-asp: 0.4
#| code-line-numbers: "6|1-6"
#| fig-alt: |
#| Dodged bar plot of average body masses of penguins by species and sex.
#| Gentoo penguins weigh more, on average, than Adelies and Chinstraps,
#| and within each species males weigh more, on average, than females.
```
## a note about this presentation
- Sometimes I'll show two options, where the *now* option is what you **should** do now.
::: columns
::: {.column width="45%"}
### previously
```{r}
# you used to do
```
:::
::: {.column width="5%"}
:::
::: {.column width="45%"}
### now
```{r}
# now you should do
```
:::
:::
<br>
. . .
- And sometimes I'll show two options, where the *now* option is what you **can** do now.
::: columns
::: {.column width="45%"}
### previously
```{r}
# you used to do
```
:::
::: {.column width="5%"}
:::
::: {.column width="45%"}
### now - optionally
```{r}
# now you can do
```
:::
:::
<br>
. . .
- There will be more of the latter than the former!
. . .
- I'll also sprinkle in some teaching tips along the way.
# tidyverse 2.0.0
## what's new in tidyverse 2.0.0?
- **lubridate** is now a core tidyverse package
- package loading message advertises the **conflicted** package
## lubridate - now core
::: columns
::: {.column width="80%"}
**lubridate**, a package that makes it easier to do the things R does with date-times, is now a core tidyerse package.
:::
::: {.column width="20%"}
![](images/lubridate.png){fig-alt="lubridate hex icon" fig-align="center"}
:::
:::
::: columns
::: {.column .fragment width="45%" fragment-index="1"}
### previously
```{r}
#| eval: false
library(tidyverse)
library(lubridate)
```
:::
::: {.column width="5%"}
:::
::: {.column .fragment width="45%" fragment-index="2"}
### now
```{r}
#| eval: false
library(tidyverse)
```
:::
:::
## lubridate - functionality
lubridate is most useful for parsing numbers or text that repsent dates into date-time:
```{r}
today_n <- 20230530
today_t <- "5/30/2023"
today_s <- "The SSA Vic May Event takes place on 30 May 2023 at 6 pm."
```
::: columns
::: {.column .fragment width="30%" fragment-index="1"}
"Easy":
```{r}
class(today_n)
ymd(today_n)
class(ymd(today_n))
```
:::
::: {.column width="3%"}
:::
::: {.column .fragment width="30%" fragment-index="2"}
Slightly more complex:
```{r}
class(today_t)
mdy(today_t)
class(mdy(today_t))
```
:::
::: {.column width="3%"}
:::
::: {.column .fragment width="30%" fragment-index="3"}
Even more complex:
```{r}
class(today_s)
dmy_h(today_s, tz = "Australia/Melbourne")
class(dmy_h(today_s))
```
:::
:::
## conflicted - now advertised {.smaller}
- Load tidyverse:
```{r}
#| warning: false
library(tidyverse)
```
```
── Attaching core tidyverse packages ──────── tidyverse 2.0.0 ──
✔ dplyr 1.1.2 ✔ readr 2.1.4
✔ forcats 1.0.0 ✔ stringr 1.5.0
✔ ggplot2 3.4.2 ✔ tibble 3.2.1
✔ lubridate 1.9.2 ✔ tidyr 1.3.0
✔ purrr 1.0.1
── Conflicts ────────────────────────── tidyverse_conflicts() ──
✖ dplyr::filter() masks stats::filter()
✖ dplyr::lag() masks stats::lag()
ℹ Use the conflicted package to force all conflicts to become errors
```
. . .
- Explicitly check for conflicts with `tidyverse::tidyverse_conflicts()`:
```{r}
tidyverse_conflicts()
```
## conflict resolution with base R
R's default conflict resolution gives precedence to the most recently loaded package
- Before loading tidyverse - calling `filter()` uses `stats::filter()`:
```{r}
#| include: false
devtools::unload("dplyr")
```
```{r}
#| error: true
penguins |>
filter(species == "Adelie")
```
. . .
- After loading tidyverse - calling `filter()` *silently* uses `dplyr::filter()`:
```{r}
#| include: false
library(dplyr)
options(dplyr.print_min = 3, dplyr.print_max = 3)
```
```{r}
penguins |>
filter(species == "Adelie")
```
## conflict resolution with conflicted
After loading conflicted - `filter()` doesn't *silently* use `dplyr::filter()`:
```{r}
#| error: true
library(conflicted)
penguins |>
filter(species == "Adelie")
```
## conflict resolution with conflicted - option 1
Pick the one you want with `::`:
```{r}
penguins |>
dplyr::filter(species == "Adelie")
```
## conflict resolution with conflicted - option 2
declare a preference with `conflicts_prefer()`:
```{r}
conflicts_prefer(dplyr::filter)
penguins |>
filter(species == "Adelie")
```
```{r}
#| include: false
options(dplyr.print_min = 6, dplyr.print_max = 6)
```
## teaching tip
::: callout-tip
## Don't hide startup messages from teaching materials
Instead, address them early on to
1. Encourage reading and understanding messages, warnings, and errors
2. Help during hard-to-debug situations resulting from base R's silent conflict resolution
But... Do teach students how to hide them in reports, particularly during editing/polishing stage!
:::
# dplyr 1.1.2
## what's new in dplyr 1.1.2?
A (non-exhaustive) list:
- Improved and expanded `_join()` functionality
- Added functionality for per operation grouping
- Quality of life improvements: `case_when()` and `if_else()`
- and more...
## improved and expanded `_join()` functionality
- New `join_by()` function for the `by` argument in `*_join()` functions
- Handling various matches (one-to-one, one-to-many, many-to-many relationships, etc.) and unmatched cases
- and more...
## `join_by()`
::: columns
::: {.column .fragment width="49%" fragment-index="1"}
### previously
```{r}
#| eval: false
#| code-line-numbers: "|4"
x |>
*_join(
y,
by = c("<x var>" = "<y var>")
)
```
:::
::: {.column width="1%"}
:::
::: {.column .fragment width="49%" fragment-index="2"}
### now - optionally
```{r}
#| eval: false
#| code-line-numbers: "|4"
x |>
*_join(
y,
by = join_by(<x var> == <y var>)
)
```
:::
:::
## setup: `islands`
We have the following information on the three islands we have penguins from:
```{r}
islands <- tribble(
~name, ~coordinates,
"Torgersen", "64°46′S 64°5′W",
"Biscoe", "65°26′S 65°30′W",
"Dream", "64°44′S 64°14′W"
)
islands
```
## `join_by()`
::: columns
::: {.column .fragment width="49%" fragment-index="1"}
**with `by`:**
```{r}
#| code-line-numbers: "4"
penguins |>
left_join(
islands,
by = c("island" = "name")
) |>
select(species, island, coordinates)
```
:::
::: {.column width="1%"}
:::
::: {.column .fragment width="49%" fragment-index="2"}
**with `join_by()`:**
```{r}
#| code-line-numbers: "4"
penguins |>
left_join(
islands,
by = join_by(island == name)
) |>
select(species, island, coordinates)
```
:::
:::
## teaching tip
::: callout-tip
## Prefer `join_by()` over `by`
So that
1. You can read it out loud as "where x is equal to y", just like in other logical statements where `==` is pronounced as "is equal to"
2. You don't have to worry about `by = c(x = y)` (which is invalid) vs. `by = c(x = "y")` (which is valid) vs. `by = c("x" = "y")` (which is also valid)
:::
## handling various matches
::: columns
::: {.column .fragment width="49%" fragment-index="1"}
### previously
```{r}
#| eval: false
*_join(
x,
y,
by
)
```
:::
::: {.column width="1%"}
:::
::: {.column .fragment width="49%" fragment-index="2"}
### now - optionally
```{r}
#| eval: false
#| code-line-numbers: "|5-7"
*_join(
x,
y,
by,
multiple = "all",
unmatched = "drop",
relationship = NULL
)
```
:::
:::
## setup: `three_penguins`
Information about three penguins, one row per `samp_id`:
```{r}
#| output-location: column
three_penguins <- tribble(
~samp_id, ~species, ~island,
1, "Adelie", "Torgersen",
2, "Gentoo", "Biscoe",
3, "Chinstrap", "Dream"
)
three_penguins
```
## setup: `weight_measurements`
Information about weight measurements of these penguins, one row per `samp_id`, `meas_id` combination:
```{r}
#| output-location: column
weight_measurements <- tribble(
~samp_id, ~meas_id, ~body_mass_g,
1, 1, 3220,
1, 2, 3250,
2, 1, 4730,
2, 2, 4725,
3, 1, 4000,
3, 2, 4050
)
weight_measurements
```
## setup: `flipper_measurements`
Information about flipper length measurements of these penguins, one row per `samp_id`, `meas_id` combination:
```{r}
#| output-location: column
flipper_measurements <- tribble(
~samp_id, ~meas_id, ~flipper_length_mm,
1, 1, 193,
1, 2, 195,
2, 1, 214,
2, 2, 216,
3, 1, 203,
3, 2, 203
)
flipper_measurements
```
## one-to-many relationships - all good!
```{r}
three_penguins |>
left_join(weight_measurements, join_by(samp_id))
```
## many-to-many relationships - warning {.smaller}
```{r}
#| include: false
options(
dplyr.print_min = 12,
dplyr.print_max = 12
)
```
::: question
What does the following warning mean?
:::
```{r}
weight_measurements |>
left_join(flipper_measurements, join_by(samp_id))
```
## many-to-many relationships - explosion of rows {.smaller}
::: question
We followed the warning's advice. Does the following look correct?
:::
```{r}
weight_measurements |>
left_join(flipper_measurements, join_by(samp_id), relationship = "many-to-many")
```
## many-to-many relationships - rethink `join_by()`
```{r}
weight_measurements |>
left_join(flipper_measurements, join_by(samp_id, meas_id))
```
## setup: `four_penguins`
Information about three penguins, one row per `samp_id`:
```{r}
#| output-location: column
four_penguins <- tribble(
~samp_id, ~species, ~island,
1, "Adelie", "Torgersen",
2, "Gentoo", "Biscoe",
3, "Chinstrap", "Dream",
4, "Adelie", "Biscoe"
)
four_penguins
```
## unmatched rows - poof!
```{r}
weight_measurements |>
left_join(four_penguins, join_by(samp_id))
```
## unmatched rows - `error`
The `unmatched` argument protects you from accidentally dropping rows during a join:
```{r}
#| error: true
weight_measurements |>
left_join(four_penguins, join_by(samp_id), unmatched = "error")
```
## unmatched rows - option 1
Use `inner_join()`:
```{r}
weight_measurements |>
inner_join(four_penguins, join_by(samp_id))
```
## unmatched rows - option 2
Set `unmatched = "drop"`:
```{r}
weight_measurements |>
left_join(four_penguins, join_by(samp_id), unmatched = "drop")
```
## unmatched rows - option 3
Do nothing -- at your own risk!
```{r}
weight_measurements |>
left_join(four_penguins, join_by(samp_id))
```
```{r}
#| include: false
options(
dplyr.print_min = 6,
dplyr.print_max = 6
)
```
## and more...
**Inequality joins** and **rolling joins**, made possible by `join_by()` being able to take expressions involving `>`, `<=`, etc.
- Learn more about inequality joins at <https://www.tidyverse.org/blog/2023/01/dplyr-1-1-0-joins/#inequality-joins>
- Learn more about rolling joins at <https://www.tidyverse.org/blog/2023/01/dplyr-1-1-0-joins/#rolling-joins>
. . .
::: callout-note
## What are inequality joins and rolling joins?
IYKYK!
If not, [R4DS, 2nd Ed - Non-equi joins section](https://r4ds.hadley.nz/joins.html#sec-non-equi-joins) is a great place to learn about them!
:::
## teaching tip
::: callout-tip
## Exploding joins can be hard to debug for students!
Teach students how to diagnose whether the join they performed, and that may not have given an error, is indeed the one they wanted to perform. Did they lose any cases? Did they gain an unexpected amount of cases? Did they perform a join without thinking and take down the entire teaching server? These things happen, particularly if students are working with their own data for an open-ended project!
:::
## added functionality for per operation grouping
::: columns
::: {.column .fragment width="49%" fragment-index="1"}
### previously
```{r}
#| eval: false
#| code-line-numbers: "|2"
df |>
group_by(x) |>
summarize(mean(y))
```
:::
::: {.column width="1%"}
:::
::: {.column .fragment width="49%" fragment-index="2"}
### now - optionally
```{r}
#| eval: false
#| code-line-numbers: "|4"
df |>
summarize(
mean(y),
.by = x
)
```
:::
:::
## persistent grouping - handle with `.groups`
::: question
Remember our "typical tidyverse pipeline"? Why did we set `.groups = "drop"` in `summarize()`?
:::
```{r}
#| code-line-numbers: "|4"
#| fig-alt: |
#| Dodged bar plot of average body masses of penguins by species and sex.
#| Gentoo penguins weigh more, on average, than Adelies and Chinstraps,
#| and within each species males weigh more, on average, than females.
penguins |>
drop_na(sex, body_mass_g) |>
group_by(species, sex) |>
summarize(mean_bw = mean(body_mass_g), .groups = "drop") |>
ggplot(aes(x = species, y = mean_bw, fill = sex)) +
geom_col(position = "dodge")
```
## persistent grouping - message
::: question
What if we don't set it? Why does `summarize()` emit a message even though the result doesn't change?
:::
```{r}
#| code-line-numbers: "4"
#| fig-alt: |
#| Dodged bar plot of average body masses of penguins by species and sex.
#| Gentoo penguins weigh more, on average, than Adelies and Chinstraps,
#| and within each species males weigh more, on average, than females.
penguins |>
drop_na(sex, body_mass_g) |>
group_by(species, sex) |>
summarize(mean_bw = mean(body_mass_g)) |>
ggplot(aes(x = species, y = mean_bw, fill = sex)) +
geom_col(position = "dodge")
```
## persistent grouping - downstream effects
::: columns
::: {.column width="49%"}
**persistent groups:**
```{r}
penguins |>
drop_na(sex, body_mass_g) |>
group_by(species, sex) |>
summarize(mean_bw = mean(body_mass_g)) |>
slice_head(n = 1)
```
:::
::: {.column width="1%"}
:::
::: {.column width="49%"}
**dropped groups:**
```{r}
penguins |>
drop_na(sex, body_mass_g) |>
group_by(species, sex) |>
summarize(mean_bw = mean(body_mass_g), .groups = "drop") |>
slice_head(n = 1)
```
:::
:::
## persistent grouping - downstream effects
::: columns
::: {.column width="49%"}
**persistent groups:**
```{r}
penguins |>
drop_na(sex, body_mass_g) |>
group_by(species, sex) |>
summarize(mean_bw = mean(body_mass_g)) |>
gt::gt()
```
:::
::: {.column width="1%"}
:::
::: {.column width="49%"}
**dropped groups:**
```{r}
penguins |>
drop_na(sex, body_mass_g) |>
group_by(species, sex) |>
summarize(mean_bw = mean(body_mass_g), .groups = "drop") |>
gt::gt()
```
:::
:::
## handling grouping - option 1
What we've already seen, explicitly selecting what to do with groups with `.groups`:
::: columns
::: {.column width="49%"}
**drop groups:**
```{r}
#| code-line-numbers: "6"
penguins |>
drop_na(sex, body_mass_g) |>
group_by(species, sex) |>
summarize(
mean_bw = mean(body_mass_g),
.groups = "drop"
)
```
:::
::: {.column width="1%"}
:::
::: {.column width="49%"}
**keep groups:**
```{r}
#| code-line-numbers: "6"
penguins |>
drop_na(sex, body_mass_g) |>
group_by(species, sex) |>
summarize(
mean_bw = mean(body_mass_g),
.groups = "keep"
)
```
:::
:::
## handling grouping - option 2