What is R?
R is a language and environment for statistical computing and graphics. It is a GNU project which is similar to the S language and environment which was developed at Bell Laboratories (formerly AT&T, now Lucent Technologies) by John Chambers and colleagues...R provides a wide variety of statistical (linear and nonlinear modelling, classical statistical tests, time-series analysis, classification, clustering, ...) and graphical techniques, and is highly extensible.
Installing R
There are several examples workflows which use the R system. For these example to operate, R must be installed on the computer running the Kepler application. R can be freely downloaded from links on the R Project web site (http://www.r-project.org). Follow the instructions provided for installation. In addition, the R 'bin' directory must be added to the PATH variable on the host computer. A simple test to see if installation is correct is to open a command/terminal window and type the command 'R'. This should startup the R system and provide messages telling the user that R has been started.R ExampleWorkflows
There are several examples of using R in Kepler. Most use the RExpression actor which is described more fully in "docs/user/RExpressionActor.pdf". Most of the examples can be found in the 'workflows' subdirectoryAverage Count Data by Species | This workflow accesses a table in the local filesystem and then averages count data by species. |
EML Simple Plot | This example shows how to convert EML column data to arrays and then plot using R. This is an R version of the eml-simple-plot example. |
Local File to
DataFrame Example |
This workflow shows how to read
a local table file into R and then process the information in the table. |
Ecogrid Data Source to R DataFrame
(I) |
This example uses an EML2
Datasource as the source for an R DataFrame, passing the data as a file
name. |
Ecogrid Data Source to R DataFrame (II) | This example uses an EML2 Datasource as the source for an R DataFrame, passing the data as a Kepler 'column record' token. |
Sequence to Record Example |
This workflow shows how
sequences of values can be converted to arrays and then to a record,
creating a table which is passed to an RExpression actor. |
Linear Regression
Example |
Here, the RExpression actor is
used to carry out a linear regression calculation and plot the results |
EML Pairs Plot (from arrays) |
This workflow configures the
EML2 DataSource to supply arrays for each column. The arrays are
connected to RExpression. |
Output from RExpression |
This example shows how the
RExpressions actor can output Kepler arrays |