for 循环中的 R 错误：意外的“=”并且无法识别“i”

Question

I have this loop, where X is a tibble with 6 columns and 3000 rows:

for(i in 1:nrow(X)){if(X[i,6] = -999){
    X[i,6] <- NA
  }
} 

When I wrote the code, it was running perfectly, substituting all the -999 cells with NA. However now it is returning this error:

Error: unexpected '=' in "for(i in 1:nrow(daily_Geul)){if(daily_Geul[i,6] ="

and

Error in `[<-.tbl_df`(`*tmp*`, i, 6, value = NA) : object 'i' not found

I have also tried using '==' instead of '=', but I get the same error back. As for the second error, I am confused as i should be defined by the for loop. I don't know how to correct these, as until yesterday the loop was working fine.

Thank you in advance for your help, as sorry if the issue is basic :)

Answer 1

try this:

assuming X is your DataFrame and that your datatype in X[i,6] is not Character

for(i in 1:nrow(X)){
    if(X[i,6] == -999){
    X[i,6] = NA
  }
}