There was a time when people pretty much ignored the distinction between MB and MiB in computer applications, and using the binary version was usually assumed because, well, this _is_ memory we are measuring. I think this is a leftover from that time.
On July 1, 2024 6:33:43 AM PDT, "Sauer, Lukas Daniel" <sa...@imbi.uni-heidelberg.de> wrote: >Hello, > >I am profiling memory usage using utils::Rprof() and subsequently summarizing >the profile using utils::summaryRprof(). According to the documentation >?summaryRprof, the option `memory = "both"` reports "memory consumption in Mb >in addition to the timings", i.e. the unit is megabytes. However, looking at >the source code >(https://github.com/wch/r-source/blob/18652de8890d89563b923ff58b45ccb04d9955fe/src/library/utils/R/summRprof.R#L170) > suggests that memory is reported in mebibytes (division by 1048576 and not by >100000). This is in line with the following minimal example: > >use_mb <- function(){a <- runif(1000000)} >use_mib <- function(){b <- runif(1024^2)} >Rprof("Rprof.out", memory.profiling=TRUE) >use_mb() >use_mib() >Rprof(NULL) >summaryRprof("Rprof.out", memory="both") > >Do not source this code, but execute it line by line. This example returns the >output: > >$by.self > self.time self.pct total.time total.pct mem.total >"runif" 0.04 100 0.04 100 15.6 > >$by.total > total.time total.pct mem.total self.time self.pct >"runif" 0.04 100 15.6 0.04 100 >"use_mb" 0.02 50 7.6 0.00 0 >"use_mib" 0.02 50 8.0 0.00 0 > >$sample.interval >[1] 0.02 > >$sampling.time >[1] 0.04 > >The example was run under: > >R version 4.4.0 (2024-04-24 ucrt) >Platform: x86_64-w64-mingw32/x64 >Running under: Windows 11 x64 (build 22631) > >If the unit were megabytes, I would expect mem.total to be 16.4, 8.0, and 8.4 >-- but rather it is 15.6, 7.6, and 8.0. Do you agree that this behavior is >unexpected or did I overlook something? If yes, I will file a bug report and >suggest that the documentation is changed to "memory consumption in MiB in >addition to the timings". > >Best regards, > >Lukas D Sauer >Biometrician >Institute of Medical Biometry > >Heidelberg University Hospital | Im Neuenheimer Feld 130.3 | D-69120 Heidelberg >Tel. +49 6221 56-35036 | Fax. +49 6221 56-4195 | E-Mail: >sa...@imbi.uni-heidelberg.de >biometrie.uni-heidelberg.de | twitter.com/imbi_heidelberg > >______________________________________________ >R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see >https://stat.ethz.ch/mailman/listinfo/r-help >PLEASE do read the posting guide http://www.R-project.org/posting-guide.html >and provide commented, minimal, self-contained, reproducible code. -- Sent from my phone. Please excuse my brevity. ______________________________________________ R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
