Nodejs cannot find R for r-integration package [Ubuntu] - r

Question

I have installed r-integration via npm. I have placed my R script inside the node-server directory which is located at srv/nodeserver/. I have R installed in my machine.
> whereis R
R: /usr/bin/R /usr/lib/R /etc/R /usr/local/lib/R /usr/share/R /usr/share/man/man1/R.1.gz
The nodejs REST API code looks like below:
app.get('/getRresult',(req,res)=>{
let result = R.executeRScript(
'server.R',"circumference",{r:2});
console.log(result)
});
When I hit the RESTAPI url I get the following error:
Error: R not found, maybe not installed.
However R is installed because if I type R in the terminal R shell opens up. I tried exporting the path of usr/bin/R in ~/.bashrc. It still does not seem to work. I am confused which path will actually work or how to set the path for ubuntu PATH variable.

Answer 1

You needs to install R on your ubuntu.
Here are steps
#1 Install the dependencies necessary
to add a new repository over HTTPS:
$ sudo apt install dirmngr gnupg apt-transport-https ca-certificates software-properties-common
#2 Add the CRAN repository to your system sources’ list
$ sudo apt-key adv --keyserver keyserver.ubuntu.com --recv-keys E298A3A825C0D65DFD57CBB651716619E084DAB9
$ sudo add-apt-repository 'deb https://cloud.r-project.org/bin/linux/ubuntu focal-cran40/'
#3 Install R
$ sudo apt install r-base
#4 Verify R version
R --version
Terminal Output
$ R --version
R version 3.6.3 (2020-02-29) -- "Holding the Windsock"
Copyright (C) 2020 The R Foundation for Statistical Computing
Platform: x86_64-pc-linux-gnu (64-bit)
R is free software and comes with ABSOLUTELY NO WARRANTY.
You are welcome to redistribute it under the terms of the
GNU General Public License versions 2 or 3.
For more information about these matters see
https://www.gnu.org/licenses/.
#5 Finally run simple example
test.js will call test.R by R.executeRScript()
It will return value into test.js then it will console.log()
file name save as test.js
const R = require('r-integration');
let result = R.executeRScript("./test.R");
console.log(result);
file name save as test.R
x <- 5
y <- 6
z <- 3
result <- max(x, y, z)
print(result)
Install r-integration library
npm install r-integration
Run it and see the Result
$ node test.js
[ 6 ]
References
R-integration - Node JS API
How to Install R on Ubuntu 20.04