R时间段重叠

Question

使用R中的"lubridate"包,我可以看出两个时间段是否重叠.但有没有一种有效的方法来计算它们重叠的天数.(例如,女性在怀孕期间吸烟的天数.怀孕期和吸烟期可能完全重叠,部分或完全不重叠)

以下是三位女性的例子:

preg_start<-as.Date(c("2011-01-01","2012-01-01","2013-01-01"))
preg_end<-preg_start+270 # end after 9 months
smoke_start<-as.Date(c("2011-02-01","2012-08-01","2014-01-01"))
smoke_end<-smoke_start+100 # all three smoked 100 days

data<-data.frame(cbind(preg_start,preg_end,smoke_start,smoke_end))

我想添加一个变量,说第一个女人在怀孕期间吸烟100天,第二个吸烟30天,第三个怀孕时不吸烟.

Answer 1

使用interval用于妊娠和吸烟创建时间间隔.然后计算intersect这些间隔.从那以后你可以计算出period天数.

library("lubridate")
preg_start<-as.Date(c("2011-01-01","2012-01-01","2013-01-01"))
preg_end<-preg_start+270 # end after 9 months
smoke_start<-as.Date(c("2011-02-01","2012-08-01","2014-01-01"))
smoke_end<-smoke_start+100 # all three smoked 100 days

smoke <- new_interval(smoke_start, smoke_end, tzone="UTC")
preg <- new_interval(preg_start, preg_end, tzone="UTC")
day(as.period(intersect(smoke, preg), "days"))

我在怀孕期间吸烟100,57和0天.