Apply a function via hash table

This function extracts the unique input values, applies the given function to it to create a hash table (containing unique input/output combinations), and then matches the original input to the hash table to obtain the desired output.

Usage

apply_fn_via_hash_table(x, fn, ...)

Arguments

x

A vector data that needs a function applied to it.

fn

A function that will be applied to x.

...

Arguments that will be passed to `fn`.

Details

This can dramatically speed up computation if there is a lot of data and a limited amount of unique values.