-----Original Message-----
From: r-help-bounces at r-project.org [mailto:r-help-bounces at r-
project.org] On Behalf Of Adriana Pitea
Sent: Wednesday, May 01, 2013 3:42 PM
To: r-help at r-project.org
Subject: [R] Sum objects in a column between an interval defined by
conditions on another column
This comes as an application to this question:
http://stackoverflow.com/questions/5896648/sum-object-in-a-column-
between-an-interval-defined-by-another-
column/5897695#comment23166107_5897695
What I would like to know is how to adjust the answer if I want to sum
the values in B, for ((A[i+1]-A[i]==0) or (A[i+1]-A[i]==1) or (A[i]-
A[i-1]==0) or (A[i]-A[i-1]==1)) where i is the row index, so basically
sum B rows for A-s that have the same value +/- 1, but not sum the same
row twice?
I tried building a loop function but I get stuck when using row indices
with data frames. So if I have the next data frame:
df
A B
[1,] 1 4
[2,] 1 3
[3,] 3 5
[4,] 3 7
[5,] 4 3
[6,] 5 2
The result I would obtain(considering that when I have ), would be:
df
A B
[1,] 1 7
[2,] 3 15
[3,] 5 2
- Nanami
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