¿Cat() Call could be missing on Launch.R? at unexpected string in json at position 4

[letrape]

I've starting using this library for an android speed detection app wich requires to process the data with R.

I am exposing the result data trought an API, so the app can use the result.

Well first I have faced several problems to run my algorithm within Node.js some solutions was:

1. install all libraries via Rscript inside the server console not vía needs (you must use install.package and specify a repo)

2)Check if Rscript is in the path and check if the lib folder for installing packages has write permissions in order to use Needs

3. Install the latest Pull Requests, the master branch has some bugs, reviewing and installing the pull-request in this repo helped me a lot

Well finally I've get stucked on an error from node

ERROR:

unexpected string in json at position 4

It was because the return of the launch.R file was [1] "[35.636]" , where 35.363 is the result of my R algorithm.

I've tried with other results such as data frames and the result was the same [1] "[x1][x2]..."

The problem is that the double quotes are not a valid JSON format

then after hours of thinking, I've decided to call cat( ) function in the Launch.R file and all my problems gone

Replacing this line

do.call(toJSON, .e$out)

with:

output <- do.call(toJSON, .e$out)
cat(output)
My question is:

My workaround is correct? or Im missing something ?