将字符串列转换为数字

Question

我的数据集Smarket（来自库ISLR）有一个方向列

  Direction    
1  Up       
2  Down      
3  Down      
4  Up       
5  Down       
6  Up

如何将其转换为二进制列，如

  Direction    
1  0       
2  1       
3  1       
4  0      
5  1       
6  0       

执行以下操作我什么都没得到。我该怎么办？

data <- Smarket 
data$Direction <- as.factor(as.numeric(data$Direction))    

Answer 1

df1$binary <- as.integer( df1$Direction == 'Down' )
df1
#   Direction binary
# 1        Up      0
# 2      Down      1
# 3      Down      1
# 4        Up      0
# 5      Down      1
# 6        Up      0

数据：

df1 <- structure(list(Direction = structure(c(2L, 1L, 1L, 2L, 1L, 2L),
                                            .Label = c("Down", "Up"),
                                            class = "factor")),
                 .Names = "Direction", class = "data.frame", 
                 row.names = c(NA, -6L))