我正在努力尝试在R中执行操作而不会崩溃。我给你一个可重复的例子。我有X:
X <- data.frame(V1 = c("chr1","chr1","chr1"),Start = c(0,1001,3002,4059,6581),Stop = c(1000,3001,4058,6580,7002),A = c(10,4,5,6,9),B = c(923,39,9,93),C = c(239,2,13,5))
我想执行此操作:
for (row in 1:nrow(X)){
X$A <- (X$A / (X[row,"Stop"] - X[row,"Start"])) * mean(X$Stop - X$Start)
X$B <- (X$B / (X[row,"Start"])) * mean(X$Stop - X$Start)
X$C <- (X$C / (X[row,"Start"])) * mean(X$Stop - X$Start)
}
当我的文档大得多(例如2.000.000行)时,出现我的问题。有什么方法可以在如此大的data.frame中更快地执行此操作?