本文介绍了逐行累计和的处理方法,对大家解决问题具有一定的参考价值,需要的朋友们下面随着小编来一起学习吧!
问题描述
我有一个data.table dt如下.
df <- data.frame(t1 = rep(0,5), t3 = c(12, 5, 8,9, 5), t7= c(25, 48, 7, 9, 14)) dt <- setDT(df) dt t1 t3 t7 1: 0 12 25 2: 0 5 48 3: 0 8 7 4: 0 9 9 5: 0 5 14我想获得各列的累积总和.我只是在行中得到它.如何在 data.table 中执行此操作.
I want to get the cumulative sums across the columns. I am only getting it across the rows. How to do this in data.table.
dt[, 1:3 := cumsum(dt)] dt t1 t3 t7 1: 0 12 25 2: 0 17 73 3: 0 25 80 4: 0 34 89 5: 0 39 103想要的输出如下:
dt t1 t3 t7 1: 0 12 37 2: 0 5 53 3: 0 8 15 4: 0 9 18 5: 0 5 19 推荐答案另一个选项使用 Reduce 和 accumulate=TRUE:
Another option use Reduce with accumulate=TRUE:
dt[, names(dt) := Reduce(`+`, dt, accumulate = TRUE)] dt # t1 t3 t7 #1: 0 12 37 #2: 0 5 53 #3: 0 8 15 #4: 0 9 18 #5: 0 5 19更多推荐
逐行累计和
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