summarize 動詞

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David Robinson

Chief Data Scientist, DataCamp

資料轉換與視覺化

擷取資料

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 動詞

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

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

彙整單一年份

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

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

彙整為多欄位

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

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

可用於彙整的函式

mean
sum
median
min
max

一起來練習吧！

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