Thank you @justyy for your comments! Yeah, it is great to come back! Let me explain a little bit.

<ol> <li>As an R package, the R codes must be put in a folder named 'R'. Otherwise, the package cannot be compiled or accepted by CRAN, as far as I know. <li>Yes, <code>zzz.Rneeds a better name. <li>Yes, a better documentation will be available in the future. I did it too soon. <li>I agree. I will write a tutorial later. <p dir="auto">Happy New year.