title: "kmeans.ddR README" author: "Vishrut Gupta, Arash Fard" date: "2015-10-26"

Start the parallel backend with 2 instances

library(ddR)
library(kmeans.ddR)
nInst = 2
useBackend(parallel,executors = nInst)

Generate some data:

K = 10 clusters, ncol = 10 features, nrow ~ 1000 observations

ncol = 100
nrow = 1000000
nrow = as.integer(nrow/nInst)
K = 10

Generate centers of clusters

centers = 100*matrix(rnorm(K*ncol),nrow = K)

Generate observations of features

generateRFData <- function(id, centers, nrow, ncol) {
	offsets = matrix(rnorm(nrow*ncol),nrow = nrow,ncol = ncol)
	cluster_ids = sample.int(nrow(centers),nrow,replace = TRUE)
	feature_obs = centers[cluster_ids,] + offsets
	features <- data.frame(cluster_ids, feature_obs)
}
features <- dmapply(generateRFData,id = 1:nInst,
                MoreArgs = list(centers = centers, nrow = nrow, ncol = ncol),
		output.type = "dframe", 
		combine = "rbind", nparts = c(nInst,1))
colnames(features) <- paste("X",1:ncol(features),sep="")

Example of dkmeans function on distributed data

training_time <- system.time({model <- dkmeans(features,K)})[3]
cat("training dkmeans model on distributed data: ", training_time,"\n")

Locally gathering data to run normal kmeans on centralized data

feature <- collect(feature)

Example of kmeans on centralized data

training_time <- system.time({model <- kmeans(feature, K, algorithm = "Lloyd")})[3]
cat("training normal kmeans model on centralized data: ", training_time,"\n")

How to Contribute

You can help us in different ways:

1. Reporting issues.
2. Contributing code and sending a Pull Request.

In order to contribute the code base of this project, you must agree to the Developer Certificate of Origin (DCO) 1.1 for this project under GPLv2+:

By making a contribution to this project, I certify that:

(a) The contribution was created in whole or in part by me and I have the 
    right to submit it under the open source license indicated in the file; or
(b) The contribution is based upon previous work that, to the best of my 
    knowledge, is covered under an appropriate open source license and I 
    have the right under that license to submit that work with modifications, 
    whether created in whole or in part by me, under the same open source 
    license (unless I am permitted to submit under a different license), 
    as indicated in the file; or
(c) The contribution was provided directly to me by some other person who 
    certified (a), (b) or (c) and I have not modified it.
(d) I understand and agree that this project and the contribution are public and
    that a record of the contribution (including all personal information I submit 
    with it, including my sign-off) is maintained indefinitely and may be 
    redistributed consistent with this project or the open source license(s) involved.

To indicate acceptance of the DCO you need to add a Signed-off-by line to every commit. E.g.:

Signed-off-by: John Doe <john.doe@hisdomain.com>

To automatically add that line use the -s switch when running git commit:

$ git commit -s