CODEWITHSUNDEEP
rinsertrows
SSP
SSP

Reputation: 77

Inserting rows based on the values in r by groups

I would like to insert rows based on the values in a column by groups. For example, in the following example, I have two observations for group A and one observation for group B. And I am interested in creating the output data frame. Output data frame include 2days before and after the date in the input data frame. (e.g., Group A (100-2,100-1,100,100+1,100+2))

Input: 

Group   Date
A   100
A   15
B   35

Output

Group   Date
A   98
A   99
A   100
A   101
A   102
A   13
A   14
A   15
A   16
A   17
B   33
B   34
B   35
B   36
B   37

Upvotes: 1

Views: 104

Answers (1)

akrun
akrun

Reputation: 887108

We can use data.table

library(data.table)
setDT(df1)[, .(Date = seq((Date-2), Date+2, by = 1)), .(Group, n = 1:nrow(df1))
                    ][, n := NULL][]
#    Group Date
# 1:     A   98
# 2:     A   99
# 3:     A  100
# 4:     A  101
# 5:     A  102
# 6:     A   13
# 7:     A   14
# 8:     A   15
# 9:     A   16
#10:     A   17
#11:     B   33
#12:     B   34
#13:     B   35
#14:     B   36
#15:     B   37

Upvotes: 1

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