Table to R

Converts a KNIME data table into a data frame which is accessible within R as knime.in.

More details about R:
http://www.r-project.org/
Short-refcard.pdf

Options

R Snippet

R Script

Examples

Take the input column "d", compute students t-test and store the p-value in the flow variable p.value:

h <- t.test(knime.in["d"])
knime.flow.out <- list(p.value = h[["p.value"]])

Read the data from the file defined by the flow variable fname. The data object will be sent to the output:

data <- read.table(knime.flow.in[["fname"]])

Column List

The list contains the columns that are available in the input table. Double click any of the column names to insert the respective field in the expression editor.

Flow Variable List

The list contains the flow variables that are currently available at the node input. Double clicking any of the entries will insert the respective identifier at the current cursor position.

Templates

Category

A template category defined by the author.

Title

Name of the template.

Description

A brief overview of the purpose of the template.

Preview

The code to be applied to your expression editor.

Advanced

Send Row Names to R

Whether to send the row names from KNIME to R. Disabling this can improve performance with very large tables. Row names of knime.in will instead be default R row names: 1:n.

R type for knime.in

By default knime.in is data.frame. For large input tables, using data.table is likely more memory efficient especially while sending the input data to R and may therefore be faster. Please be aware that the support for data.table is experimental (!) and requires the "data.table" R package to be installed. It may not work for some R scripts, may slightly change or even be removed entirely in a future version.

Send batch size

The input of the R node is sent in row batches (default, 10 000 rows at a time). This is the amount of rows KNIME will retain in memory at any given time. For large tables, a higher batch size may be faster, but will require additional memory. Be aware, that R will likely keep all of the input table in memory and this only helps with memory during transmission of data to R.

Overwrite default path to R home

Check this option to select a path to the home of a R installation that is different from the path configured on the R preference page. The path must point to the root folder of the R installation tree. You can either specify the path directly or use the R installation in a conda environment. The conda environment can be specified using a conda environment flow variable from e.g. a “Conda Environment Propagation” node.

Views

R Std Output

The text sent to standard out during the execution of R executable as well as the text of the .Rout file generated by R.

R Error Output

The text sent to standard error during the execution of R executable as well as the text of the .Rout file generated by R. (If it appears in gray, it's the output of a previously failing run which is preserved for your trouble shooting.)

Workflows

• 00_Topic_Modeling_with_Verified_ComponentsKNIME Hub
• 00_Topic_Modeling_with_Verified_ComponentsKNIME Hub
• 01_Example_of_R_SnippetKNIME Hub
• 01_Example_of_R_SnippetKNIME Hub
• 01_R SnippetノードKNIME Hub
• Show all 101 workflows

Links

• R to Table and as.Date functionby JanDuo on 2020-06-12

  forum.knime.com/p/94121
• R nodes hangby mlauber71 on 2019-02-04

  forum.knime.com/p/54096
• reader and writer Rby JanDuo on 2020-07-28

  forum.knime.com/p/98251

Developers