摘要: f <- function(start_time) { start_time <- as.POSIXct(start_time) dt <- difftime(Sys.time(), start_time, units="secs") # Since you only want the H:M... 阅读全文
posted @ 2014-07-22 18:13 emanlee 阅读(9215) 评论(0) 推荐(0) 编辑