In ggplot/facet_wrap(), how to marke axis Y have different format ? Thanks!
 library(tidyverse)
    test_data <- diamonds
    plot_data <- test_data %>% mutate(x_to_price=x/price,
                                      price=price*1000) %>% head(12) %>% 
      mutate(mseq=1:NROW(.)) %>% 
      select(price,x_to_price,mseq) %>% gather(key='type',value='amount',- mseq)
    
    
    plot_data %>% ggplot(aes(x=mseq,y=amount))+geom_line()+geom_point()+
      facet_wrap(.~type,scales='free_y')

 
    
