NCA Software for R

The NCA software is free software that can be used with the free programming language R. 

======VERSION 4.0.0 is available======

The main NCA specific functions are nca_analysis for conducting NCA,  nca_output for printing and plotting results of the analysis, and nca_outliers for evaluating potential outliers. More information can be found  on

If you have installed an older version of the NCA package you can update the package as follows:


The NCA package uses other packages. It is possible that these packages are not installed on your computer. In that case the following error message may appear: 'There is no package called …' , where … corresponds to the name of the missing package. You then need to install the specific packages first.


If you install the package for the first time: see the Quick Start Guide. A novice user without knowledge of R or NCA can install the software on the user’s computer and perform an NCA analysis within 15 minutes. 

The Quick Start Guide and a demonstration shows how NCA can be done in three steps.

The software draws ceiling lines and produces several NCA parameters (including necessity effect size). An example is shown here.

A video explanation of the bottleneck table , and a video demonstration on how to produce the bottleneck table with the NCA software are available.