Add column for max of next 10 rows [duplicate] - r

Question

This question already has answers here:
Finding maximum value in column
(2 answers)
Closed 5 years ago.
I am trying to add a column to my dataframe which contains the maximum value of the next ten rows of another column (High). In the example below, the max for the first row would be 92.83. I am new to using R and am having some issues doing so.
Date_Time High Max_Next10
2014-06-30 08:35:00 92.55 92.83
2014-06-30 08:40:00 92.69 92.83
2014-06-30 08:45:00 92.63 92.83
2014-06-30 08:50:00 92.83 92.80
2014-06-30 08:55:00 92.80 92.76
2014-06-30 09:00:00 92.71 92.76
2014-06-30 09:05:00 92.76 92.72
2014-06-30 09:10:00 92.72 92.75
2014-06-30 09:15:00 92.70 92.75
2014-06-30 09:20:00 92.70 92.75
2014-06-30 09:25:00 92.70 92.75
2014-06-30 09:30:00 92.63 92.76
2014-06-30 09:35:00 92.63 92.76
2014-06-30 09:40:00 92.57 N/A
2014-06-30 09:45:00 92.59 N/A
2014-06-30 09:50:00 92.58 N/A
2014-06-30 09:55:00 92.72 N/A
2014-06-30 10:00:00 92.75 N/A
2014-06-30 10:05:00 92.69 N/A
2014-06-30 10:10:00 92.66 N/A
2014-06-30 10:15:00 92.75 N/A
2014-06-30 10:20:00 92.76 N/A
2014-06-30 10:25:00 92.72 N/A

Answer 1

There is a package called zooand a function called rollmax
One simple line get your result.
df$Max_Next10=zoo::rollmax(df$High, 10, na.pad = TRUE,align='left')
> df
Date_Time High Max_Next10
1 6/30/2014 8:35 92.55 92.83
2 6/30/2014 8:40 92.69 92.83
3 6/30/2014 8:45 92.63 92.83
4 6/30/2014 8:50 92.83 92.83
5 6/30/2014 8:55 92.80 92.80
6 6/30/2014 9:00 92.71 92.76
7 6/30/2014 9:05 92.76 92.76
8 6/30/2014 9:10 92.72 92.72
9 6/30/2014 9:15 92.70 92.75
10 6/30/2014 9:20 92.70 92.75
11 6/30/2014 9:25 92.70 92.75
12 6/30/2014 9:30 92.63 92.75
13 6/30/2014 9:35 92.63 92.76
14 6/30/2014 9:40 92.57 92.76
15 6/30/2014 9:45 92.59 NA
16 6/30/2014 9:50 92.58 NA
17 6/30/2014 9:55 92.72 NA
18 6/30/2014 10:00 92.75 NA
19 6/30/2014 10:05 92.69 NA
20 6/30/2014 10:10 92.66 NA
21 6/30/2014 10:15 92.75 NA
22 6/30/2014 10:20 92.76 NA
23 6/30/2014 10:25 92.72 NA

Answer 2

A solution with sapply:
df$Max_Next10 <- sapply(seq_len(nrow(df)), function(i){
if(i + 10 > nrow(df))
NA
else
max(df$High[(i + 1):(i + 10)])
})
The data I started with:
# > dput(df)
structure(list(Date_Time = c("2014-06-30 08:35:00", "2014-06-30 08:40:00",
"2014-06-30 08:45:00", "2014-06-30 08:50:00", "2014-06-30 08:55:00",
"2014-06-30 09:00:00", "2014-06-30 09:05:00", "2014-06-30 09:10:00",
"2014-06-30 09:15:00", "2014-06-30 09:20:00", "2014-06-30 09:25:00",
"2014-06-30 09:30:00", "2014-06-30 09:35:00", "2014-06-30 09:40:00",
"2014-06-30 09:45:00", "2014-06-30 09:50:00", "2014-06-30 09:55:00",
"2014-06-30 10:00:00", "2014-06-30 10:05:00", "2014-06-30 10:10:00",
"2014-06-30 10:15:00", "2014-06-30 10:20:00", "2014-06-30 10:25:00"
), High = c(92.55, 92.69, 92.63, 92.83, 92.8, 92.71, 92.76, 92.72,
92.7, 92.7, 92.7, 92.63, 92.63, 92.57, 92.59, 92.58, 92.72, 92.75,
92.69, 92.66, 92.75, 92.76, 92.72)), .Names = c("Date_Time",
"High"), row.names = c(NA, -23L), class = "data.frame")

Answer 3

You could create a function that takes a data frame and column name as parameters, and for each row, calculates the max of the next 10 rows of the referenced column:
mk.next10 <- function (data, col) {
count <- 10
c(
sapply(1:(nrow(data) - count), function(i) max(data[(i+1):(i+1+count),col], na.rm=T)),
rep(NA, count)
)
}
With this, you could create the column for the data frame:
data$Max_Next10 <- mk.next10(data, 'High')

Answer 4

In the code below, the dataframe we are working with is named test. Change accordingly, for your case.
# Initialise
rm(list = ls())
library(data.table)
library(plyr)
# Load/Create data
test <- data.frame(value=c(300,100,200,50,100,80,100,700,500,300,250,510,100,620,910))
# Add index
test$id <- seq.int(nrow(test))
# Count number of rows
n <- nrow(test)
# Loop to create variable with Max
for(i in 1:n) {
test_i <- subset(test,id>=i & id < i+10)
max_test_i <- max(test_i$value)
setDT(test)[i, Max:= max_test_i]
}
The output is:
value id Max
300 1 700
100 2 700
200 3 700
50 4 700
100 5 700
80 6 910
100 7 910
700 8 910
500 9 910
300 10 910
250 11 910
510 12 910
100 13 910
620 14 910
910 15 910