summarize 动词

Tidyverse 入门

David Robinson

Chief Data Scientist, DataCamp

数据转换与可视化

提取数据

gapminder %>%
  filter(country == "United States", year == 2007)

# A tibble: 1 x 6
        country continent  year lifeExp       pop gdpPercap
          <fct>     <fct> <int>   <dbl>     <dbl>     <dbl>
1 United States  Americas  2007  78.242 301139947  42951.65

summarize 动词

gapminder %>%
  summarize(meanLifeExp = mean(lifeExp))

# A tibble: 1 x 1
  meanLifeExp
        <dbl>
1    59.47444

汇总某一年

gapminder %>%
  filter(year == 2007) %>%
  summarize(meanLifeExp = mean(lifeExp))

# A tibble: 1 x 1
  meanLifeExp
        <dbl>
1    67.00742

汇总到多列

gapminder %>%
  filter(year == 2007) %>%
  summarize(meanLifeExp = mean(lifeExp),
            totalPop = sum(pop))

# A tibble: 1 x 2
  meanLifeExp   totalPop
        <dbl>      <dbl>
1    67.00742 6251013179

可用于汇总的函数

mean
sum
median
min
max

Passons à la pratique !

Tidyverse 入门