Enhanced Thiessen Polygon Method with 99.9% of Maximum Size Threshold

[YaoTingYao]

Incorporated the remove_edge_cells function, contributed by @agcopenhaver in Issue #3, to improve the Thiessen Polygon Method by ensuring polygons maintain up to 99.9% of their maximum size. This modification facilitates the inclusion of more samples while accepting minor irregularities in some edge polygon shapes.

The decision to set the threshold at 99.9%—as opposed to 99%—addresses concerns over the impact of irregular edges. With a standard assessment grid cell area of 100,000 ha, a 1% translates to a significant area of 10 km^2. By adjusting the threshold to 99.9%, the maximum discrepancy is reduced to a more manageable 1 km^2 (0.1%), having a better balance between polygon integrity and sample inclusivity.

Using Para as an example :

The original Method

99% Threshold
Applying the 99% method yields pink polygons, allowing for more sample inclusion but results in some edge polygons have irregular square shape. A 1% criterion equates to an area of 10 km^2.

99.9% Threshold
Adopting the 99.9% method generates blue polygons, which similarly improve the number of samples while ensuring edge polygons exhibit less irregularity. In this case, a 0.1% criterion corresponds to an area of 1 km^2.

[YaoTingYao]

Hi @agcopenhaver, thank you for your valuable contribution of the remove_edge_cells function. We'd like to suggest implementing a 99.9% threshold and have accordingly updated the relevant scripts. Could you please review the PR at your convenience? Cheers!

[agcopenhaver]

LGTM