R Tutorial

The purpose of this tutorial is to walk the new user through a basic K-means analysis using H₂O through R. The objective is to learn the basic syntax of H₂O through R, including importing and parsing files, specifying a model, and obtaining model output.

Those who have never used H₂O before should see the quick start guide for additional instructions on how to run H₂O. Additionally, users who are using H₂O through R for the first time will need to install the R package, available in our download package at: http://0xdata.com/downloadtable/.

Getting Started

Before beginning, be sure to have an instance of H₂O running. Additionally, users who are using H₂O for the first time can find help for installing the R package at http://docs.0xdata.com/Ruser/Rh2opackage.html.

Step-by-step

Step 1 Call the H₂O package, and initialize H₂O in R. Note that an object “H2Oconn” was created. Assigning the H₂O initialization to an object is important, because the connection will be used later to tell R where to send data sets, model specification, and where to find results.

library(h2o)
H2Oconn<- h2o.init(ip = "localhost", port = 54321)

When the R package and the current running version of H₂O match, the returned message tells users they are successfully connected. However, users may see notification that indicates a mismatch between the R package and running jar. In that case, the R package and jar can be made to match by following the prompts in the R console.

Step 2

Import data files, and inspect the data.

swiss.hex<- h2o.importFile(H2Oconn, "../smalldata/swiss.csv",
+ key="swiss.hex")

summary(swiss.hex)

Summary will return output similar to the following:

Step 3

Fit a K-means model. The model specified here sets centers (the number of clusters) to 4, and asks for a model on the columns Fertility, Agriculture, Examination, Education, Catholic, and Infant.Mortality. Iter.max specifies the maximum number of iterations the algorithm should complete.

fit.kmeans<- h2o.kmeans(data=swiss.hex, centers=4,
+ cols=c("Fertility", "Agriculture", "Examination", "Education",
+ "Catholic", "Infant.Mortality"), iter.max=10)

The output of this model:

fit.kmeans

Additional Notes

The data set used in this model is “swiss”, and is included as part of the base R package. Users can view the data in its original incarnation by typing swiss at the prompt in their R console, or can view the summary of the data by requesting summary(swiss)

swiss
summary(swiss)

View your work in R through GUI When the session was initialized, a connection to a running instance of H ₂O was made by specifying an IP and port. Users can point their web browsers at that same IP and port to view the work from their R session in the GUI.