如何使用for循环更改列中的值

I want to change the values of column based on an if-else conditions and am using FOR loop to do that. The data is shown below:

我想根据if-else条件更改列的值，并使用FOR循环来实现这一点。数据如下:

m1 m2 m3 a1 a2
0.5 0.7 0.2 10 20
0.1 0 0.2 30 40

I want to apply the following condition

我想应用以下条件。

ifelse(column > 0.5,1,0)

I tried using this code, but its not working:

我试过用这个代码，但是没用:

for (k in 1:3){
  data$m[k] <- ifelse(data$m[k] > 0.5,1,0)
  }

I also tried using double square brackets [[ ]], but that's also not working. I used the same logic for a list which worked fine, but in this case the column names are string and am not sure how to change the code accordingly.

我也尝试过使用双方括号[]，但也不起作用。我对一个运行良好的列表使用了相同的逻辑，但是在这种情况下，列名是字符串，我不知道如何相应地更改代码。

1 个解决方案

#1

See bellow code, i think you will expecting this...

看看下面的代码，我想你会期待这个…

m<-data.frame(
  m1=c(0.5,0.1),
  m2=c(0.7,0),
  m3=c(0.2,0.2),
  a1=c(10,30),
  a2=c(20,40)
)

for(i in 1:3){
  m[,i]<-ifelse(m[,i]>0.5,1,0)
}

result is:

结果是:

m1 m2 m3 a1 a2
0  1  0 10 20
0  0  0 30 40

#1