Is learning R programming language for machine learning worth it?

I already know python.

unless you're required to do so, stick with python. Although R suite it's fairly easy to use.

You'll need:
Pandas: data analysis framework
https://pandas.pydata.org/

NumPy: Math framework
https://numpy.org/

Jupyter Notebook: A interactive page to display and manipulate data
https://jupyter.org/

and you may read the doing data analysis in python book from O'Riley.
https://amazon.com/gp/product/...

@heyheni

I been doing machine learning in python.

I know numpy,pandas,and other common machine learning library/framework.

Since the Harvard university is teaching in R (https://edx.org/professional-certif...) , I thought I will check out what is the big deals about R.

Is this some kind of cash grab or maybe I am missing something?

@mr-user if you've got the cash.
there is a cheaper option though.
Doing Data is a learning plattform for data analysis where you also can learn R. https://www.datacamp.com/

@heyheni

I am trying to obtain a certificate. I can't just say I know the technology (even though I know it) , I need to have a paper-based proof.

There’s larger audience and support for python on ML

Take a look to scikit-learn.org and forget about R. R is great for data analysis but if you want machine learning go all the way with python.

What @franlopezd said
Python with libs for the ML part,

For analysis and visualization I’d highly recommend R. Making a violin plot is literally a three/liner. (Plus a line for output as pdf)