emptyInit-package: emptyInit

In naolsen/emptyInit: Empty initializations.

Description

emptyInit is a small package for fast initialization of numeric-type vectors. Intended only for experienced R users.

Why use it?: By default, R assigns NA or 0 to all elements whenever a vector, matrix or array is initialized using numeric, matrix or array.

This is a waste if you're going to overwrite all the elements anyway, e.g. by looping over columns. Therefore, emptyInit only allocates memory, but does not assign nor check values (and thus, whatever was in the memory beforehand will be the values of your vector)

What to be aware of?: As the memory can contain whatever values, the values are not likely to be of any sense and should be overwritten.

Is it safe?: It is complety safe, but there is no reproducibility.

Is it fast?: The computational speed is O(1) + time(memory allocation), the latter which is handled internally by R. For small n (~ < 1000), numeric is faster, but for large n emptyInit is many times faster.

What about vectorization? Well, if you can vectorize your code, this would likely be a better option. But vectorization can require much work and your code might depend on some functions that are not vectorizable.

Author(s)

Niels Olsen

naolsen/emptyInit documentation built on May 23, 2019, 5:07 p.m.