In R, how to transform a matrix wtih 2 columns into a multimap like structure

Posted by Derek on Stack Overflow See other posts from Stack Overflow or by Derek
Published on 2010-03-19T14:59:19Z Indexed on 2010/03/19 15:11 UTC
Read the original article Hit count: 423

Filed under:

r

|

list

|

array

|

multimap

Hi,

I am wondering if there is a way to transform a matrix of 2 column into a multimap or list of list.

The first column of the matrix is an id (with possibly duplicated entries) and the 2nd column is some value.

For example, if I have to following matrix

m<-matrix(c(1,2,1,3,2,4), c(3,2))

i would like to transform it into the following list

[[1]]
3,4
[[2]]
2

Thanks,

Derek

Related posts about list

kernel module compiling error

as seen on Ask Ubuntu - Search for 'Ask Ubuntu'
sh@ubuntu:/home/ccpp/helloworld$ make gcc-4.6 -O2 -DMODULE -D_KERNEL_ -W -Wall -Wstrict-prototypes -Wmissing-prototypes -isystem /lib/modules/`uname -r`/build/include -c -o hello-1.o hello-1.c hello-1.c:4:0: warning: "MODULE" redefined [enabled by default] <command-line>:0:0: note: this is… >>> More
SEO: Nested List vs List, Split Over Divs vs Definition List

as seen on Pro Webmasters - Search for 'Pro Webmasters'
From an SEO perspective which, if any, is better: Option 1: Nested lists with h2 tags <ul id="mainpoints"> <li><h2>Powerful Analysis</h2> <ul> <li>Charting and indicators</li> <li>Daily trading signals</li> … >>> More
ASA hairpining: I basicaly want to allow 2 spokes to be able to communicate with each other.

as seen on Server Fault - Search for 'Server Fault'
ASA Spoke to Spoke Communication I have been looking at spke to spoke comms or "hairpining" for months and have posted on numerouse forums but to no avail. I have a Hub and spoke network where the HUB is an ASA Firewall version 8.2 * I basicaly want to allow 2 spokes to be able to communicate with… >>> More
How to remove a package entirely?

as seen on Ask Ubuntu - Search for 'Ask Ubuntu'
Hi I'm quite new to Linux, but before using it I was hearing that Windows programs, after uninstallation, leaves a lot of remains on the hard disc, and Linux removes all. I'm using Ubuntu 10.04. To uninstall packages I'm using sudo apt-get autoremove application_name or sudo aptitude purge application_name… >>> More
Update a list from another list

as seen on Stack Overflow - Search for 'Stack Overflow'
I have a list of users in local store that I need to update from a remote list of users every once in a while. Basically: If a remote user already exists locally, update its fields. If a remote user doesn't already exist locally, add the user. If a local user doesn't appear in the remote list, deactivate… >>> More

Developer IT

In R, how to transform a matrix wtih 2 columns into a multimap like structure - Developer IT

In R, how to transform a matrix wtih 2 columns into a multimap like structure

r

list

array

multimap

Related posts about r

Related posts about list

kernel module compiling error

SEO: Nested List vs List, Split Over Divs vs Definition List

ASA hairpining: I basicaly want to allow 2 spokes to be able to communicate with each other.

How to remove a package entirely?

Update a list from another list

Categories cloud