Update values of a column based on predefined thresholds - r

Question

I have a data set as follows
Name Price
A 100
B 123
C 112
D 114
E 101
F 102
I need a way to update the value in the price column if the price is between +3 or -3 of a vector of values specified to the value specified in the vector. The vector may contain any number of elements.
Vector = c(100,111)
Updated dataframe
Name Price
A 100
B 123
C 111
D 111
E 100
F 100
If the vector is
Vector = c(104,122)
then the updated dataframe needs to be
Name Price
A 100
B 122
C 112
D 114
E 104
F 104

Answer 1

df <- data.frame('Name' = LETTERS[1:6], 'Price'= c(100,123,112,114,101,102))
transform <- function(value, conditionals){
for(cond in conditionals){
if(abs(value - cond) < 4){
return(cond)
}
}
return(value)
}
sapply(df$Price, transform, c(104,122))
This should work. It can probably done in one line with apply (but I find it difficult to read sometimes so this should be easier to read).

Answer 2

Here's one approach
bound <- 3
upper_bound <- Vector+bound
lower_bound <- Vector-bound
vi <- Reduce("pmax", lapply(seq_along(Vector), function(i) i*(df$Price <= upper_bound[i] & df$Price >= lower_bound[i])))
# [1] 1 0 2 2 1 1
vi_na <- replace(vi, vi == 0, NA)
# [1] 1 NA 2 2 1 1
df$Price <- dplyr::mutate(df, Price = ifelse(is.na(Vector[vi_na]), Price, Vector[vi_na]))
# Name Price.Name Price.Price
# 1 A A 100
# 2 B B 123
# 3 C C 111
# 4 D D 111
# 5 E E 100
# 6 F F 100
Data
df <- read.table(text = "Name Price
A 100
B 123
C 112
D 114
E 101
F 102", header=TRUE)
Vector = c(100,111)