我想将多项式系数附加到data.frame,如下所示:
df1 <-
structure(list(
Y = c(4, 4, 4, 4, 4, 8, 8, 8, 8, 8, 16, 16, 16,
16, 16, 32, 32, 32, 32, 32, 4, 4, 4, 4, 4, 8, 8, 8, 8, 8, 16,
16, 16, 16, 16, 32, 32, 32, 32, 32, 4, 4, 4, 4, 4, 8, 8, 8, 8,
8, 16, 16, 16, 16, 16, 32, 32, 32, 32, 32)),
class = "data.frame", row.names = c(NA, -60L))
library(tidyverse)
df1 %>%
dplyr::mutate(
Linear = poly(x = Y, degree = 3, raw = TRUE)[ ,1]
, Quadratic = poly(x = Y, degree = 3, raw = TRUE)[ ,2]
, Cubic = poly(x = Y, degree = 3, raw = TRUE)[ ,3]
)
我想知道是否有一个像这样的简洁方法
df1 %>%
dplyr::mutate(poly(x = Y, degree = 3, raw = TRUE))
谢谢
答案 0 :(得分:7)
与您希望的方式不完全相同,但是足够接近。我首先将poly
(矩阵)的输出转换为data.frame,然后使用!!!
拼接列(将list / data.frame的每个元素转换为自己的参数)。 setNames
对于重命名列是可选的:
library(dplyr)
df1 %>%
mutate(!!!as.data.frame(poly(x = .$Y, degree = 3, raw = TRUE))) %>%
setNames(c("Y", "Linear", "Quadratic", "Cubic"))
结果:
Y Linear Quadratic Cubic
1 4 4 16 64
2 4 4 16 64
3 4 4 16 64
4 4 4 16 64
5 4 4 16 64
6 8 8 64 512
7 8 8 64 512
8 8 8 64 512
9 8 8 64 512
10 8 8 64 512
11 16 16 256 4096
12 16 16 256 4096
13 16 16 256 4096
14 16 16 256 4096
15 16 16 256 4096
16 32 32 1024 32768
17 32 32 1024 32768
18 32 32 1024 32768
19 32 32 1024 32768
20 32 32 1024 32768
...
答案 1 :(得分:2)
另一个选择,尽管我真的很喜欢@useR的解决方案:
df1 %>%
left_join(data.frame(Y = unique(.$Y), poly(unique(.$Y), degree = 3, raw = TRUE)),
by = c('Y' = 'Y')) %>%
setNames(c('Y', 'Linear', 'Quadratic', 'Cubic'))
Y Linear Quadratic Cubic
1 4 4 16 64
2 4 4 16 64
3 4 4 16 64
4 4 4 16 64
5 4 4 16 64
6 8 8 64 512
7 8 8 64 512
8 8 8 64 512
9 8 8 64 512
10 8 8 64 512
11 16 16 256 4096
12 16 16 256 4096
13 16 16 256 4096
14 16 16 256 4096
15 16 16 256 4096
16 32 32 1024 32768
17 32 32 1024 32768
18 32 32 1024 32768
19 32 32 1024 32768
20 32 32 1024 32768