仅删除具有NA值的列

Question

我正在使用此命令删除所有值都为NA的列。

testing5 <- subset(testing4,
                   select = -c(kurtosis_picth_belt, skewness_roll_belt, 
                   skewness_roll_belt.1, min_yaw_belt, amplitude_yaw_belt, 
                   kurtosis_roll_arm, kurtosis_picth_arm, kurtosis_yaw_arm, 
                   skewness_roll_arm, skewness_pitch_arm, kurtosis_picth_dumbbell, 
                   skewness_roll_dumbbell, skewness_pitch_dumbbell, min_yaw_dumbbell, 
                   kurtosis_roll_forearm, kurtosis_picth_forearm, skewness_roll_forearm, 
                   skewness_pitch_forearm))

是否有更短的（程序化）方法？

谢谢和问候， 帕塔

Answer 1

您可以删除包含所有NA值的列，例如

d <- data.frame(x = c(NA, 3, NA), y = rep(NA, 3))
#    x  y
# 1 NA NA
# 2  3 NA
# 3 NA NA

d[!sapply(d, function(x) all(is.na(x)))]
#    x
# 1 NA
# 2  3
# 3 NA

关于您的数据，这将是

testing4[!sapply(testing4, function(x) all(is.na(x)))]

Answer 2

使用@Richards数据的另一种方式（更多矢量化）

d[!is.nan(colMeans(d, na.rm = TRUE))]
#    x
# 1 NA
# 2  3
# 3 NA

Answer 3

tidyverse方法如下所示（也使用@Rich Scriven数据）：

d %>% select_if(~any(!is.na(.)))
#    x
# 1 NA
# 2  3
# 3 NA