所以我有一个data.table
,我需要填写基于列的索引值,然后也是基于占位符。例:
V1 V2 V3 V4
Row1 1 1 a d
Row2 1 1 a d
Row3 1 1 a d
Row4 1 2 a h
Row5 1 2 a h
Row6 1 2 a h
Row7 2 1 b i
Row8 2 1 b i
Row9 2 1 b i
Row10 2 2 b t
Row11 2 2 b t
Row12 2 2 b t
....
Row350k ...
我需要弄清楚是怎么写的与沿列1的指数滑动参考语句分配的for
循环。基本上
对于每一列索引,一次一个:
V1 = 1
和V2 = 1
替换字符 'a' 与0.0055 + RNORM(1,0.0055,0.08)一次迭代。V1 = 1
和V2 = 2
替换字符 'a' 与0.0055 + RNORM(1,0.0055,0.08)一次迭代。 (相同的变化,但与RNORM的另一迭代)V1 = 2
和V1 = 1
,用0.0055 + RNORM一次迭代替换字符 'B'(1,0.01)V1 = 2
和V1 = 1
,用0.0055 + RNORM(1,0.01)一次迭代(相同的变化,但与RNORM的另一次迭代)替换字符“b”。等了col1和col2的每递增值。实际上它的20+行,而不是仅仅2第二个索引。
那么所需的输出是:
Col1 Col2 Col3 Col4
Row1 1 1 0.00551 d
Row2 1 1 0.00551 d
Row3 1 1 0.00551 d
Row4 1 2 0.00553 h
Row5 1 2 0.00553 h
Row6 1 2 0.00555 h
Row7 2 1 0.0011 i
Row8 2 1 0.0011 i
Row9 2 1 0.0011 i
Row10 2 2 0.0010 t
Row11 2 2 0.0010 t
Row12 2 2 0.0010 t
....
Row350k ...
只是不知道,因为在COL1的值被重复了一定NUM如何与一个循环做到这一点。列1具有300K加值,以使得滑动环圈需要动态可扩展性。
这是我曾尝试:
for (i in seq(1, 4000, 1))
{for (ii in seq(1, 2, 1)) {
data.table[V3 == "a" , V3 := 0.0055 + rnorm(1, 0.0055, 0.08)]
data.table[V3 == "b" , V3 := 0.0055 + rnorm(1, 0.001, 0.01)]
}}
谢谢!
如果我理解你的问题正确,这可能会有帮助。
library(data.table)
dt <- data.table(V1 = c(rep(1, 6), rep(2, 6)),
V2 = rep(c(rep(1, 3), rep(2, 3)), 2),
V3 = c(rep("a", 6), rep("b", 6)),
V4 = c(rep("d", 3), rep("h", 3), rep("i", 3), rep("t", 3)))
# define a catalog to join on V3 which contains the parameters for the random number generation
catalog <- data.table(V3 = c("a", "b"),
const = 0.0055,
mean = c(0.0055, 0.001),
std = c(0.08, 0.01))
# for each value of V3 generate .N (number of observations of the current V3 value) random numbers with the specified parameters
dt[catalog, V5 := i.const + rnorm(.N, i.mean, i.std), on = "V3", by = .EACHI]
dt[, V3 := V5]
dt[, V5 := NULL]
好了,所以我想通了,我是不正确递增我的柜台。对于在第一列4000级的场景的每个与所述第二柱11次重复一个矩阵/数据表我用follwing:
Col1counter <- 1
Col2counter <- 1
for(Col1counter in 1:4000) {
for(col2counter in 1:11) {
test1[V1 == col1counter & V2 == col2counter & V3 == "a" , V55 := 0.00558 + rnorm(1, 0.00558, 2)]
col2counter+ 1
}
Col1counter+ 1}
在条件语句中使用这两个指数可以确保它通过行准确抓取。