通过gc()默默释放内存

Question

我在ubuntu中运行R代码并想释放一些内存.删除(rm())变量后,我调用gc().它似乎有效.但是如何让它在沉默中工作(即不报告消息).我试图设置gcinfo(verbose=FALSE),但gc()仍然报告该消息.

gcinfo(verbose=FALSE)
# [1] FALSE
gc()
#             used  (Mb) gc trigger   (Mb)  max used   (Mb)
# Ncells    256641  13.8     467875   25.0    350000   18.7
# Vcells 103826620 792.2  287406824 2192.8 560264647 4274.5

Answer 1

该invisible()功能对此非常有用.一种方法是编写gc()自己的一个小包装函数,没有任何参数gc()无形地返回.

gcQuiet <- function(quiet = TRUE, ...) {
    if(quiet) invisible(gc()) else gc(...)
}

gcQuiet()        ## runs gc() invisibly

gcQuiet(FALSE)
#          used (Mb) gc trigger (Mb) max used (Mb)
# Ncells 283808 15.2     531268 28.4   407500 21.8
# Vcells 505412  3.9    1031040  7.9   896071  6.9

gcQuiet(FALSE, verbose=TRUE)
# Garbage collection 26 = 12+1+13 (level 2) ... 
# 15.2 Mbytes of cons cells used (53%)
# 3.9 Mbytes of vectors used (49%)
#          used (Mb) gc trigger (Mb) max used (Mb)
# Ncells 283813 15.2     531268 28.4   407500 21.8
# Vcells 505412  3.9    1031040  7.9   896071  6.9