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.
