How to increase resolution of the data function

[Michael Pickering]

I have two questions that are somewhat related to each other:

1) How can I change the heat map resolution For example, how can I half the size of the boxes which are generated using the TERR function

2) What kind of interpolation is this function performing Are there ways to easily customize between polynomial or linear interpolation I do not know enough about R scripts to determine this answer.

Thank you!