Error in Math.factor(x) : ‘abs’ not meaningful for factors

Posted 2021-09-14 Data+Science+Insight

Error in Math.factor(x) : ‘abs’ not meaningful for factors

Error in Math.factor(x_fac): \'abs\' not meaningful for factors
Traceback:

1. Math.factor(x_fac)
2. stop(gettextf("%s not meaningful for factors", sQuote(.Generic)))

问题：

factor变量使用abs函数会报错哦，，，

x <- c(- 5, 9, 3, - 1, 2)                 # Create example vector
# -5  9  3 -1  2


x_fac <- factor(x)                        # Convert example vector to factor
x_fac                                     # Print output to RStudio console
# [1] -5 9  3  -1 2 
# Levels: -5 -1 2 3 9
abs(x_fac)                                # Apply abs function to factor
# Error in Math.factor(x_fac) : \'abs\' not meaningful for factors

解决：

# 把factor转化为数值型变量才可以

x_num <- as.numeric(as.character(x_fac))  # Convert factor to numeric
x_num_abs <- abs(x_num)