bike2 <- read.table("bike_sharing_data.txt", sep="\t", header=TRUE)
bike3 <- read.csv("bike_sharing_data.csv")
bike4 <- read.delim("bike_sharing_data.txt")
class(bike2$humidity)
## [1] "character"
bike2[6251, "season"]
## [1] 4
table(bike2$season)[4]
## 4
## 4232
sum(bike2$windspeed > 40 & bike2$season %in% c(1,4) )
## [1] 46