1 object 존재 여부 체크

2 apply류

3 패키지들

4 The Overlap Coefficient

5 R 레퍼런스 카드

exists(as.character(substitute(fit1)))

• http://stackoverflow.com/questions/3505701/r-grouping-functions-sapply-vs-lapply-vs-apply-vs-tapply-vs-by-vs-aggrega
  
• http://www.ats.ucla.edu/stat/r/library/advanced_function_r.htm
  
• https://nsaunders.wordpress.com/2010/08/20/a-brief-introduction-to-apply-in-r/
  
  

• SparkRext(http://mockquant.blogspot.jp/2015/07/sparkrext-sparkr-extension-for-closer.html)
  
• RcppRedis(http://dirk.eddelbuettel.com/code/rcppredis.html)
  
  

• http://www.r-bloggers.com/the-overlap-coefficient/
  
  

• http://cafe.naver.com/foralla/2313