HI Farnoosh,
Not sure I understand the expected output. The difference between the first 2
days is "136 days"
May be this helps
library(data.table)
dcast.data.table(setDT(df)[, list(Visit=.N, Diff=
as.numeric(abs(diff(as.Date(Date, format='%d-%b-%y'))))) ,
by = ID], ID+Visit~ Diff, value.var='Diff', length)
ID Visit 136 255 857
1: 1 2 1 0 0
2: 2 3 0 1 1
On Wednesday, February 11, 2015 5:47 PM, farnoosh sheikhi
<farnoosh...@yahoo.com> wrote:
Hi Arun,
I have a data set that look s like below. I wanted to get a difference in dates
for each unique ID and record it as a new X and have binary input for each one.
ID Date
1 06-Sep-13
1 20-Jan-14
2 06-Mar-12
2 25-Jun-11
2 29-Oct-13
For example for the first two date for ID=1 ( 20-Jan-14 - 06-Sep-13 ~ 121) and
I want the data to be like follow:
ID Visit 121
1 2 1
2 3 0
I really appreciate if you can help me with this. I know I need to write some
kind of loop, but I don't know how to think of the logic behind it.
Thanks a lot.
Farnoosh
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