Explain the PGD matlab code and theory behind it

Job ID: 33400019

Budget: $10 – $30 USD

Proper generalized decomposition PGD is an order reduction technique.
The book found in the link below provides an implementation of PGD in matlab to solve Poisson equation in 4 variations.
I need someone to explain to me the matlab codes in the book and the theory behind them. The successful bidder should possess deep knowledge on the topic of PGD. The explanation can be done through a zoom meeting in english or french or arabic.
Link for the book:
https://link.springer.com/book/10.1007/978-3-319-29994-5