tidyverse数据筛选

---
title: "R Notebook"
output: html_notebook
---


```{r}
library(tidyverse)
starwars %>% 
select(sex,height,mass,species) %>%
  mutate(height=height/100)  %>%
  filter(species =="Human")  %>%
  group_by(sex) %>%
  summarise( mean(height,na.rm = TRUE))
 
```