Lab3.md

Laba 3

1

> add2 <- function(arg1, arg2) {
+ return(arg1+arg2)
+ }
> add2(5, 8)
[1] 13

2

> above <- function(vector, n = 10) {
+ return (vector[vector > n])
+ }
> above(c(2, 5, 7, 10, 12))
[1] 12
> above(c(2, 5, 7, 10, 12), 5)
[1]  7 10 12

3

> my_ifelse <- function(vector_x, exp, n) {
+ switch(exp,
+ "<"={
+ return(vector_x[vector_x<n])
+ },
+ ">"={
+ return(vector_x[vector_x>n])
+ },
+ "<="={
+ return(vector_x[vector_x<=n])
+ },
+ ">="={
+ return(vector_x[vector_x>=n])
+ },
+ "=="={
+ return(vector_x[vector_x==n])
+ },
+ {
+ return(vector_x)
+ }
+ )
+ }
> my_ifelse(c(1, 2, 3), "Ґ", 5)
[1] 1 2 3
> my_ifelse(c(1, 2, 3, 8, 9), "<", 5)
[1] 1 2 3

4

> columnmean <- function(x, removeNA = TRUE) {
+ for(i in seq_len(ncol(x))) {
+ print(mean(x[,i], trim=0, na.rm=removeNA))
+ }
+ }

> mat_na = matrix( c(1, NA, 4, 8), 2, 2 )
> mat_na
     [,1] [,2]
[1,]    1    4
[2,]   NA    8
> columnmean(mat_na)
[1] 1
[1] 6
> columnmean(mat_na, FALSE)
[1] NA
[1] 6
> d_frame <- data.frame(abc = 1:4, vjuk = 3:6)
> columnmean(d_frame)
[1] 2.5
[1] 4.5