如何在for循环中的多个变量数据帧中替换零？

Question

So I have 1,000 dataframes to process using a FOR loop in R, say they are named DF1 to DF1000. I need to replace all 0 values within the data frames to 1's. I try to write this as follows.

for (i in 1:1000){
eval(as.symbol(paste0("DF","i")))[eval(as.symbol(paste0("DF","i")))==0]<-1
}

This brings up an error ("could not find eval<-"). How do I resolve this issue? I tried using "assign" but get a different error ("target of assignment expands to non-language object").

Thanks in advance, Alvo

Answer 1

One way is to assign every character value DF to a new DF in the global environment, using base replace function.

for (i in 1:1000){
      assign(paste0("DF", i),
             replace(eval(parse(text = paste0("DF", i))), eval(parse(text = paste0("DF", i))) == 0, 1),
             envir = .GlobalEnv)
    }

This is similar to replace(DF,DF == 0, 1) outside the for loop.