summary.bench_mark: Summarize bench::mark results.
In bench: High Precision Timing of R Expressions

Description Usage Arguments Details Value Examples

Summarize bench::mark results.

1 2	## S3 method for class 'bench_mark' summary(object, filter_gc = TRUE, relative = FALSE, time_unit = NULL, ...)

`object`	bench_mark object to summarize.
`filter_gc`	If `TRUE` remove iterations that contained at least one garbage collection before summarizing. If `TRUE` but an expression had a garbage collection in every iteration, filtering is disabled, with a warning.
`relative`	If `TRUE` all summaries are computed relative to the minimum execution time rather than absolute time.
`time_unit`	If `NULL` the times are reported in a human readable fashion depending on each value. If one of 'ns', 'us', 'ms', 's', 'm', 'h', 'd', 'w' the time units are instead expressed as nanoseconds, microseconds, milliseconds, seconds, hours, minutes, days or weeks respectively.
`...`	Additional arguments ignored.

If filter_gc == TRUE (the default) runs that contain a garbage collection will be removed before summarizing. This is most useful for fast expressions when the majority of runs do not contain a gc. Call summary(filter_gc = FALSE) if you would like to compute summaries with these times, such as expressions with lots of allocations when all or most runs contain a gc.

A tibble with the additional summary columns. The following summary columns are computed

expression - bench_expr The deparsed expression that was evaluated (or its name if one was provided).
min - bench_time The minimum execution time.
median - bench_time The sample median of execution time.
itr/sec - double The estimated number of executions performed per second.
mem_alloc - bench_bytes Total amount of memory allocated by R while running the expression. Memory allocated outside the R heap, e.g. by malloc() or new directly is not tracked, take care to avoid misinterpreting the results if running code that may do this.
gc/sec - double The number of garbage collections per second.
n_itr - integer Total number of iterations after filtering garbage collections (if filter_gc == TRUE).
n_gc - double Total number of garbage collections performed over all iterations. This is a psudo-measure of the pressure on the garbage collector, if it varies greatly between to alternatives generally the one with fewer collections will cause fewer allocation in real usage.
total_time - bench_time The total time to perform the benchmarks.
result - list A list column of the object(s) returned by the evaluated expression(s).
memory - list A list column with results from Rprofmem().
time - list A list column of bench_time vectors for each evaluated expression.
gc - list A list column with tibbles containing the level of garbage collection (0-2, columns) for each iteration (rows).

dat <- data.frame(x = runif(10000, 1, 1000), y=runif(10000, 1, 1000))

# `bench::mark()` implicitly calls summary() automatically
results <- bench::mark(
  dat[dat$x > 500, ],
  dat[which(dat$x > 500), ],
  subset(dat, x > 500))

# However you can also do so explicitly to filter gc differently.
summary(results, filter_gc = FALSE)

# Or output relative times
summary(results, relative = TRUE)

# A tibble: 3 x 13
  expression                  min median `itr/sec` mem_alloc `gc/sec` n_itr
  <bch:expr>                <bch> <bch:>     <dbl> <bch:byt>    <dbl> <int>
1 dat[dat$x > 500, ]        452µs  601µs     1445.     507KB     8.00   723
2 dat[which(dat$x > 500), ] 342µs  417µs     2194.     258KB     8.00  1097
3 subset(dat, x > 500)      606µs  743µs     1265.     510KB    12.0    633
# … with 6 more variables: n_gc <dbl>, total_time <bch:tm>, result <list>,
#   memory <list>, time <list>, gc <list>
# A tibble: 3 x 13
  expression                  min median `itr/sec` mem_alloc `gc/sec` n_itr
  <bch:expr>                <dbl>  <dbl>     <dbl>     <dbl>    <dbl> <int>
1 dat[dat$x > 500, ]         1.32   1.44      1.13      1.97     1.00   719
2 dat[which(dat$x > 500), ]  1      1         1.72      1        1     1093
3 subset(dat, x > 500)       1.77   1.78      1         1.98     1.52   627
# … with 6 more variables: n_gc <dbl>, total_time <bch:tm>, result <list>,
#   memory <list>, time <list>, gc <list>