day1_exercise2
#1
ch = c("0","21","12","16")
#2
y = as.numeric(ch)
y = sort(y)
y
#3
y2 = seq(0,24,by=8)
y2
#4
sum((y < y2) == (y<=y2))
#5
x = seq(from=1,by=2,length=30)
x
#6
rep(c(T,F),times=5)
#7
sum(x[x>10 & x<20])
#8
xmat = matrix(x,6,5,byrow=T)
#9
z = list(
sumr=apply(xmat,1,sum),
meanc=apply(xmat,2,mean),
varc=apply(xmat,2,var))
z
day1_exercise2.txt · Last modified: 2021/03/17 13:09 by 127.0.0.1