Removing empty rows of a data file in R

Question

I have a dataset with empty rows. I would like to remove them:

myData<-myData[-which(apply(myData,1,function(x)all(is.na(x)))),]

It works OK. But now I would like to add a column in my data and initialize the first value:

myData$newCol[1] <- -999

Error in `$<-.data.frame`(`*tmp*`, "newCol", value = -999) : 
  replacement has 1 rows, data has 0

Unfortunately it doesn't work and I don't really understand why and I can't solve this. It worked when I removed one line at a time using:

TgData = TgData[2:nrow(TgData),]

Or anything similar.

It also works when I used only the first 13.000 rows.

But it doesn't work with my actual data, with 32.000 rows.

What did I do wrong? It seems to make no sense to me.

Answer 1

I assume you want to remove rows that are all NAs. Then, you can do the following :

data <- rbind(c(1,2,3), c(1, NA, 4), c(4,6,7), c(NA, NA, NA), c(4, 8, NA)) # sample data
data
     [,1] [,2] [,3]
[1,]    1    2    3
[2,]    1   NA    4
[3,]    4    6    7
[4,]   NA   NA   NA
[5,]    4    8   NA

data[rowSums(is.na(data)) != ncol(data),]
     [,1] [,2] [,3]
[1,]    1    2    3
[2,]    1   NA    4
[3,]    4    6    7
[4,]    4    8   NA

If you want to remove rows that have at least one NA, just change the condition :

data[rowSums(is.na(data)) == 0,]
     [,1] [,2] [,3]
[1,]    1    2    3
[2,]    4    6    7