319 lines
3.6 KiB
Plaintext
319 lines
3.6 KiB
Plaintext
---
|
|
title: "Data Transform"
|
|
format:
|
|
dwsd-revealjs:
|
|
logo: _extensions/drwater/dwsd/inst/ucaslogo.png
|
|
---
|
|
|
|
```{r}
|
|
#| include: false
|
|
#| cache: false
|
|
lang <- "cn"
|
|
require(tidyverse)
|
|
require(learnr)
|
|
knitr::opts_chunk$set(echo = TRUE)
|
|
```
|
|
|
|
```{r}
|
|
#| echo: false
|
|
source("../../coding/_common.R")
|
|
library(nycflights13)
|
|
library(tidyverse)
|
|
```
|
|
|
|
|
|
## `tidyverse`风格数据分析总体流程
|
|
|
|
|
|
|
|
|
|
## [dplyr cheatsheet](../../image/cheatsheet/data-transformation.pdf)
|
|
|
|
|
|
```{r}
|
|
#| echo: false
|
|
dwfun::ggsavep("../../image/cheatsheet/data-transformation.svg", loadit = TRUE)
|
|
```
|
|
|
|
|
|
|
|
## 查看数据
|
|
|
|
```{r}
|
|
flights
|
|
```
|
|
|
|
|
|
## 选择列
|
|
|
|
```{r}
|
|
#| results: false
|
|
|
|
flights |>
|
|
select(year, month, day)
|
|
```
|
|
|
|
## 选择列
|
|
|
|
```{r}
|
|
#| results: false
|
|
|
|
flights |>
|
|
select(year:day)
|
|
```
|
|
|
|
|
|
## 选择列
|
|
|
|
```{r}
|
|
flights |>
|
|
select(3:5)
|
|
```
|
|
|
|
## 选择列
|
|
|
|
```{r}
|
|
flights |>
|
|
select(!year:day)
|
|
```
|
|
|
|
## 选择列
|
|
|
|
```{r}
|
|
flights |>
|
|
select(-(year:day))
|
|
```
|
|
|
|
## 选择列
|
|
|
|
```{r}
|
|
flights |>
|
|
select(where(is.character))
|
|
```
|
|
|
|
## 选择列
|
|
|
|
```{r}
|
|
flights |>
|
|
select(!where(is.character)) |>
|
|
select(contains("_"))
|
|
```
|
|
|
|
## 选择列
|
|
|
|
```{r}
|
|
flights |>
|
|
select(tail_num = tailnum)
|
|
```
|
|
|
|
## 选择列
|
|
|
|
```{r}
|
|
flights |>
|
|
select(air_time, everything())
|
|
```
|
|
|
|
|
|
## 重命名
|
|
|
|
```{r}
|
|
flights |>
|
|
rename(tail_num = tailnum)
|
|
```
|
|
|
|
## 重命名
|
|
|
|
```{r}
|
|
flights |>
|
|
rename(年份 = 1) |>
|
|
rename(月份 = 2)
|
|
```
|
|
|
|
## 重命名
|
|
|
|
```{r}
|
|
flights |> select(1:4) |> head(n = 3)
|
|
# 重命名
|
|
flights |> select(1:4) |> head(n = 3) |> rename_all(~ c("c1", "c2", "c3", "c4"))
|
|
```
|
|
|
|
## 重命名
|
|
|
|
```{r}
|
|
flights |> select(1:4) |> head(n = 3)
|
|
# 重命名
|
|
flights |> select(1:4) |> head(n = 3) |> rename_all(toupper)
|
|
```
|
|
|
|
|
|
## 重命名
|
|
|
|
```{r}
|
|
flights |> select(1:4) |> head(n = 3)
|
|
# 重命名
|
|
flights |>
|
|
select(1:4) |>
|
|
head(n = 3) |>
|
|
rename_all(~ paste0(toupper(.), "_NEW"))
|
|
```
|
|
|
|
|
|
## 练习
|
|
|
|
将含有下划线的列名中的下划线去掉。
|
|
|
|
|
|
```{r}
|
|
flights |> select(1:4) |> head(n = 3)
|
|
```
|
|
|
|
|
|
## 练习
|
|
|
|
将`airqualitydf`中列名的单位信息去除（前5列）。
|
|
|
|
|
|
```{r}
|
|
airqualitydf <- readxl::read_xlsx("../../data/airquality.xlsx", sheet = 2)
|
|
airqualitydf |> select(1:5)
|
|
```
|
|
|
|
|
|
|
|
## `filter`
|
|
|
|
```{r}
|
|
flights |>
|
|
filter(dep_delay > 120)
|
|
```
|
|
|
|
## filter 练习
|
|
|
|
Flights that departed on January 1.
|
|
|
|
```{r}
|
|
#| echo: false
|
|
flights |>
|
|
filter(month == 1 & day == 1)
|
|
```
|
|
|
|
## filter 练习
|
|
|
|
|
|
Select flights that departed in January or February
|
|
|
|
```{r}
|
|
#| echo: false
|
|
flights |>
|
|
filter(month %in% c(1, 2))
|
|
```
|
|
|
|
## filter 练习
|
|
|
|
```{r}
|
|
jan1 <- flights |>
|
|
filter(month == 1 & day == 1)
|
|
```
|
|
|
|
## filter
|
|
|
|
```{r}
|
|
#| error: true
|
|
#| eval: false
|
|
|
|
flights |>
|
|
filter(month = 1)
|
|
```
|
|
|
|
## filter
|
|
|
|
```{r}
|
|
flights |>
|
|
filter(month == 1 | 2)
|
|
```
|
|
|
|
## 排序
|
|
|
|
```{r}
|
|
flights |>
|
|
arrange(year, month, day, dep_time)
|
|
```
|
|
|
|
## 排序
|
|
|
|
```{r}
|
|
flights |>
|
|
arrange(desc(dep_delay))
|
|
```
|
|
|
|
## slice
|
|
|
|
```{r}
|
|
flights |> head(n = 5)
|
|
flights |> slice(1:5)
|
|
```
|
|
|
|
## slice
|
|
|
|
```{r}
|
|
flights |>
|
|
slice_max(dep_delay, n = 5)
|
|
```
|
|
|
|
## slice
|
|
|
|
```{r}
|
|
flights |>
|
|
slice_min(dep_delay, prop = 0.005)
|
|
```
|
|
|
|
## 排序练习
|
|
|
|
根据`origin`、`dest`、`air_time`倒序排序。
|
|
|
|
```{r}
|
|
#| echo: false
|
|
flights |>
|
|
arrange(origin, dest, desc(air_time)) |>
|
|
select(origin, dest, air_time, everything())
|
|
```
|
|
|
|
|
|
## 去重
|
|
|
|
```{r}
|
|
# Remove duplicate rows, if any
|
|
flights |>
|
|
distinct()
|
|
```
|
|
|
|
## 去重
|
|
|
|
```{r}
|
|
# Find all unique origin and destination pairs
|
|
flights |>
|
|
distinct(origin, dest)
|
|
```
|
|
|
|
## 去重
|
|
|
|
```{r}
|
|
flights |>
|
|
distinct(origin, dest, .keep_all = TRUE)
|
|
```
|
|
|
|
|
|
|
|
## 欢迎讨论！{.center}
|
|
|
|
```{r}
|
|
#| results: 'asis'
|
|
rmdify::slideend(
|
|
wechat = FALSE,
|
|
type = "public",
|
|
tel = FALSE,
|
|
thislink = "../"
|
|
)
|
|
```
|
|
|