This note shares an experiment comparing the performance of a number of data processing systems available in
R. Our notional or example problem is finding the top ranking item per group (group defined by three string columns, and order defined by a single numeric column). This is a common and often needed task.
Continue reading Timings of a Grouped Rank Filter Task
R package is really good at sorting. Below is a comparison of it versus
dplyr for a range of problem sizes.
Continue reading data.table is Really Good at Sorting
In this note we will show how to speed up work in
R by partitioning data and process-level parallelization. We will show the technique with three different
dplyr. The methods shown will also work with base-
R and other packages.
For each of the above packages we speed up work by using
wrapr::execute_parallel which in turn uses
wrapr::partition_tables to partition un-related
data.frame rows and then distributes them to different processors to be executed.
rqdatatable::ex_data_table_parallel conveniently bundles all of these steps together when working with
The partitioning is specified by the user preparing a grouping column that tells the system which sets of rows must be kept together in a correct calculation. We are going to try to demonstrate everything with simple code examples, and minimal discussion.
Continue reading Speed up your R Work
rquery is an
R package for specifying data transforms using piped Codd-style operators. It has already shown great performance on
rqdatatable is a new package that supplies a screaming fast implementation of the
rquery system in-memory using the
rquery is already one of the fastest and most teachable (due to deliberate conformity to Codd’s influential work) tools to wrangle data on databases and big data systems. And now
rquery is also one of the fastest methods to wrangle data in-memory in
R (thanks to
data.table, via a thin adaption supplied by
Continue reading rqdatatable: rquery Powered by data.table
I would like to demonstrate some helpful
R notation tools that really neaten up your
Img: Christopher Ziemnowicz.
Continue reading Supercharge your R code with wrapr
“Base R” (call it “Pure R”, “Good Old R”, just don’t call it “Old R” or late for dinner) can be fast for in-memory tasks. This is despite the commonly repeated claim that: “packages written in C/C++ are (edit: “always”) faster than R code.”
The benchmark results of “rquery: Fast Data Manipulation in R” really called out for follow-up timing experiments. This note is one such set of experiments, this time concentrating on in-memory (non-database) solutions.
Below is a graph summarizing our new results for a number of in-memory implementations, a range of data sizes, and two different machine types.
Continue reading Base R can be Fast
I’ve been asked if the adapter “
let” from our
replyr works with
My answer is: it does work. I am not a
data.table user so I am not the one to ask if
data.table benefits a from a non-standard evaluation to standard evaluation adapter such as
replyr::let. Continue reading Does replyr::let work with data.table?