Selecting rows based on condition in R and keep rows with missing values-CodePudding

I have a dataframe in R (dd_sub) with a column (E) and want to drop the rows where E > 0. The column has rows where E = "NA" , E < 0 and E > 0.

When I write this:

dd_subset <- dd_sub[ which( dd_sub$E < 0 | dd_sub$E == "NA"), ]

I only get the row where E < 0.

Is there a way to solve this?

CodePudding user response：

You don't need to use which(). You can just declare the condition - which returns a logical array - so the rows whose position is TRUE in the condition are selected.

Also, dd_sub$E == "NA" match a string 'NA', not the definition of missing value. is.na() returns TRUE in the positions where the value is missing.

dd_subset <- dd_sub[dd_sub$E < 0 | is.na(dd_sub$E), ]

Other possibility is to write the negative - with ! - of the rows you want to drop.

dd_subset <- dd_sub[! dd_sub$E >= 0]