timandrews335 / r-functions-performance

R functions performance measurement

r-functions-performance

This repo was created with the purpose of studying performance of different functions that can be used to obtain the same result.

How it Works

We are using "Melbourne Housing Market" public dataset provided by Kaggle with 60.7k observations and 13 columns to test some functions.

We run the selected function 1000 times over one column using microbenchmark R package and use summary() to analyse the difference in milliseconds between the functions.

Performance Result

subset functions

Subset column in dataframe

function	times	unit	lq	uq	min	max	median	avg
base1	1000	ms	0.046	0.070	0.029	7.155	0.051	0.069
base2	1000	ms	0.046	0.070	0.028	0.719	0.051	0.062
select	1000	ms	3.026	3.385	2.300	171.330	3.163	3.603

to string functions

Convert column as character

function	times	unit	lq	uq	min	max	median	avg
as.character	1000	ms	9.294	9.561	8.753	26.156	9.417	9.670
formatC	1000	ms	18.431	20.064	17.091	149.821	18.836	20.896
paste	1000	ms	14.372	14.779	13.418	32.034	14.562	14.937
toString	1000	ms	16.637	17.086	15.707	41.926	16.866	17.279
sprintf	1000	ms	17.489	17.929	16.577	44.356	17.697	18.154

mapping functions

Apply a specific function to a list or vector.

function	times	unit	lq	uq	min	max	median	avg
lapply	1000	ms	24.797	36.303	21.462	177.460	25.461	29.437
sapply	1000	ms	45.477	57.340	41.955	191.467	46.537	50.650
map	1000	ms	59.256	71.623	54.824	216.958	69.014	69.942
map_chr	1000	ms	60.548	70.826	49.809	228.917	68.514	69.210

to date functions

Convert column to date format

function	times	unit	lq	uq	min	max	median	avg
lubridate	1000	ms	15.960	25.373	15.044	149.830	17.809	22.262
to.date	1000	ms	26.657	28.798	24.899	160.471	26.957	30.054
strptime	1000	ms	80.131	82.893	77.475	346.436	81.040	84.660

simple pattern matching functions

Find a simple pattern in a string, and return the subset

function	times	unit	lq	uq	min	max	median	avg
grep	1000	ms	15.600	16.477	14.167	33.731	16.051	16.171
regexpr	1000	ms	20.181	21.236	18.470	158.691	20.637	21.587
sqldf	1000	ms	206.089	215.534	197.608	351.085	209.091	211.285

License

r-functions-performance is MIT Licensed. censed](LICENSE).