Error - replacement has [x] rows, data has [y]

Solution 1:

The answer by @akrun certainly does the trick. For future googlers who want to understand why, here is an explanation...

The new variable needs to be created first.

The variable "valueBin" needs to be already in the df in order for the conditional assignment to work. Essentially, the syntax of the code is correct. Just add one line in front of the code chuck to create this name --

df$newVariableName <- NA

Then you continue with whatever conditional assignment rules you have, like

df$newVariableName[which(df$oldVariableName<=250)] <- "<=250"

I blame whoever wrote that package's error message... The debugging was made especially confusing by that error message. It is irrelevant information that you have two arrays in the df with different lengths. No. Simply create the new column first. For more details, consult this post https://www.r-bloggers.com/translating-weird-r-errors/

Solution 2:

You could use cut

 df$valueBin <- cut(df$value, c(-Inf, 250, 500, 1000, 2000, Inf), 
    labels=c('<=250', '250-500', '500-1,000', '1,000-2,000', '>2,000'))

data

 set.seed(24)
 df <- data.frame(value= sample(0:2500, 100, replace=TRUE))

Solution 3:

TL;DR ...and late to the party, but that short explanation might help future googlers..

In general that error message means that the replacement doesn't fit into the corresponding column of the dataframe.

A minimal example:

df <- data.frame(a = 1:2); df$a <- 1:3

throws the error

Error in $<-.data.frame(*tmp*, a, value = 1:3) : replacement has 3 rows, data has 2

which is clear, because the vector a of df has 2 entries (rows) whilst the vector we try to replace has 3 entries (rows).