Post With Code

This is a post with executable code.

# 编写函数
last_quarter_day = function(dates) {
  dates = as.Date(dates)
  month = as.integer(format(dates, '%m'))
  year  = as.integer(format(dates, '%Y'))
  
  quarter = ceiling(month / 3)
  day = c('12-31', '03-31', '06-30', '09-30')[quarter]
  year[quarter == 1] = year[quarter == 1] - 1 
  
  as.Date(sprintf('%d-%s', year, day))
}

# 测试函数
x = c("2021-10-14", "2019-01-11")
last_quarter_day(x)

[1] "2021-09-30" "2018-12-31"

# 系统信息
sessionInfo()

R version 4.2.3 (2023-03-15 ucrt)
Platform: x86_64-w64-mingw32/x64 (64-bit)
Running under: Windows 10 x64 (build 19045)

Matrix products: default

locale:
[1] LC_COLLATE=Chinese (Simplified)_China.utf8 
[2] LC_CTYPE=Chinese (Simplified)_China.utf8   
[3] LC_MONETARY=Chinese (Simplified)_China.utf8
[4] LC_NUMERIC=C                               
[5] LC_TIME=Chinese (Simplified)_China.utf8    

attached base packages:
[1] stats     graphics  grDevices utils     datasets  methods   base     

loaded via a namespace (and not attached):
 [1] htmlwidgets_1.6.4 compiler_4.2.3    fastmap_1.2.0     cli_3.6.2        
 [5] tools_4.2.3       htmltools_0.5.8.1 rstudioapi_0.16.0 yaml_2.3.8       
 [9] rmarkdown_2.27    knitr_1.47        jsonlite_1.8.8    xfun_0.45        
[13] digest_0.6.35     rlang_1.1.4       evaluate_0.24.0