Hi Joris,
The amount of a month ago is normally one value from another row.
But I used 'sum-sum + dataset[i,22]' because I would like to reuse the code
also for other tables. In some tables it is possible that the value of last
month is the sum of values from different rows.
Thank u for your
Hi William,
Your programs works perfect and very fast for the table I'm using right now
(only one match per row)
If I want to reuse this code other tables, it can match with more than one row.
Is it possible to adapt your code easily, if I have to sum the values of last
month from different
-Original Message-
From: Ian Willems [mailto:ian.will...@uz.kuleuven.ac.be]
Sent: Tuesday, October 20, 2009 6:46 AM
To: William Dunlap; r-help@r-project.org
Subject: RE: [R] how to get rid of 2 for-loops and optimize runtime
Hi William,
Your programs works perfect and very fast
Short: get rid of the loops I use and optimize runtime
Dear all,
I want to calculate for each row the amount of the month ago. I use a matrix
with 2100 rows and 22 colums (which is still a very small matrix. nrows of
other matrixes can easily be more then 10)
Table before
Year month
Hi Ian,
first of all, take a look at the functions sapply, mapply, lapply,
tapply, ... : they are the more efficient way of implementing loops.
Second, could you elaborate a bit further on the data set : the amount
of the month ago, is that one value from another row, or the sum of
all values in
-Original Message-
From: r-help-boun...@r-project.org
[mailto:r-help-boun...@r-project.org] On Behalf Of Ian Willems
Sent: Monday, October 19, 2009 6:50 AM
To: 'r-help@r-project.org'
Subject: [R] how to get rid of 2 for-loops and optimize runtime
Short: get rid of the loops I
6 matches
Mail list logo
