将数据帧矩阵的每一行除以 R 中长度较短的向量？

Question

我正在使用一个数据框矩阵“d”，第一列是时间，其余 5 列包含数值：

structure(c("2016-01-01 00:00:00", "2016-01-01 01:00:00", "2016-01-01 02:00:00", 
"206.000", "208.000", "208.500", "246.000", "246.000", "242.000", 
" 50.000", " 51.000", " 51.000", "207.500", "207.500", "209.000", 
NA, NA, NA), .Dim = c(3L, 6L), .Dimnames = list(NULL, c("timestamp", 
"Crow_education_Omer", "Crow_education_Keisha", "Crow_education_Kate", 
"Crow_education_Winston", "Crow_education_Marlin")))

我想将“d”的第 2 到 6 列除以向量“crow_sqm”

crow_sqm <- c(11857.4, 14173.2, 6320.2, 8659.1, 7561.4)

得到

2016-01-01 00:00:00     206.000   123.000   10.000    207.500   NA
2016-01-02 00:00:00     206.000   123.000   10.000    207.500   NA
2016-01-03 00:00:00     206.000   123.000   10.000    207.500   NA

之前我使用 as.matrix(d) 将数据帧“d”转换为矩阵并删除了 d 的第一列。当我尝试划分 d/crow_sqm 时，出现以下错误：

d/crow_sqm 中的错误：二元运算符的非数字参数

“d”当前显示在数据下，“crow_sqm”显示在值下。不确定错误是来自 NA 值还是其他原因。谁能给点建议？

谢谢。

Answer 1

你可以使用Map来制作

df[-1] <- Map("/", df[-1], crow_sqm)

这样

> df
            timestamp Crow_education_Omer Crow_education_Keisha
1 2016-01-01 00:00:00          0.01737312            0.01735670
2 2016-01-01 01:00:00          0.01754179            0.01735670
3 2016-01-01 02:00:00          0.01758396            0.01707448
  Crow_education_Kate Crow_education_Winston Crow_education_Marlin
1         0.007911142             0.02396323                    NA
2         0.008069365             0.02396323                    NA
3         0.008069365             0.02413646                    NA

数据

> dput(df)
structure(list(timestamp = c("2016-01-01 00:00:00", "2016-01-01 01:00:00",
"2016-01-01 02:00:00"), Crow_education_Omer = c(206, 208, 208.5
), Crow_education_Keisha = c(246, 246, 242), Crow_education_Kate = c(50,
51, 51), Crow_education_Winston = c(207.5, 207.5, 209), Crow_education_Marlin = c(NA,
NA, NA)), row.names = c(NA, -3L), class = "data.frame")

Answer 2

只需稍加调整，您就可以在不转换为矩阵的情况下做到这一点

df <- as.data.frame(df)
cbind(df["timestamp"], df[,-1] %>% 
  mutate(across(everything(), ~as.numeric(.))) %>% 
  purrr::map2_df(crow_sqm, ~ .x/.y))

            timestamp Crow_education_Omer Crow_education_Keisha Crow_education_Kate Crow_education_Winston Crow_education_Marlin
1 2016-01-01 00:00:00          0.01737312            0.01735670         0.007911142             0.02396323                    NA
2 2016-01-01 00:00:00          0.01754179            0.01735670         0.008069365             0.02396323                    NA
3 2016-01-01 02:00:00          0.01758396            0.01707448         0.008069365             0.02413646                    NA

如果您直接使用 df，则不需要 mutate(across..，因为在将其转换为矩阵时数据类型可能已更改

Answer 3

您可以使用sweep。

sweep(type.convert(d[, -1]), 2, crow_sqm, `/`)

#     Crow_education_Omer Crow_education_Keisha Crow_education_Kate Crow_education_Winston
#[1,]               206.0                   123                10.0                  207.5
#[2,]               208.0                   123                10.2                  207.5
#[3,]               208.5                   121                10.2                  209.0

#     Crow_education_Marlin
#[1,]                    NA
#[2,]                    NA
#[3,]                    NA

或者转置。

t(t(type.convert(d[, -1]))/crow_sqm)

数据是一个矩阵，矩阵只能包含一种类型的数据。第一列不能表示为数字，因此矩阵中的所有值都变为字符类型。 -1 用于删除矩阵中的第一列，type.convert 用于将所有列的值从字符更改为数字。