R : how to draw a filled.contour plot with a data.frame of 3 variables in R (without regular grid)?

To Access My Live Chat Page,
On Google, Search for "hows tech developer connect"

I have a hidden feature that I promised to tell you about.
This is a YouTube's feature which works on Desktop.
First, Make sure this video is playing.
Then, type the letters 'awesome' on your keyboard as the next step.
You will see a flashing rainbow instead of a regular progress bar on YouTube.

A quick introduction about me,
Howdy, my name's Delphi.
Allow me to provide support in answering your questions.
I welcome your comments and chats if you have more detailed queries.
If you have knowledge to contribute or an answer to provide, we encourage you to comment below.
Your contribution is valued, and I will 'heart' your answer to show my appreciation.