Error message: Error in sample.int(length(x), size, replace, prob) : invalid first argument

[Mosen111]

Hi
What am I doing wrong here?

x2.imp <- missForest(x2)

x2 is a data frame, all numerical values, with some missing values. I get this error:

Error in sample.int(length(x), size, replace, prob) :
invalid first argument

but when I run with the iris dataset as in the tutorial, I get no errors. Would appreciate it if you could clarify the issue for me. cheers

[sillasgonzaga]

@Mosen111 Why did you close this issue?

[Mosen111]

I guessed there was no one to answer, so I closed it.

[HenrikEckermann]

@Mosen111 : Did you find a solution to this problem? f not, It should be reopened.

[Mosen111]

Hi, I reopened it, but there is no one to answer here.

[stephematician]

A data.frame of numbers with some missing values should run without error. For example the following code works for me:

v <- rnorm(20)
v[sample(1:20, size=5)] <- NA
x2 <- as.data.frame(matrix(v, nrow=5))
missForest(x2)

Try debug(missForest) and investigate at what point the code fails, then compare it to what happens when using the iris data.

[Mosen111]

thanks but too technical for me, I have already found alternatives that work smoothly. cheers

[kkmann]

I had a similar issue before, was caused by a sloppy type check in missForest but should be resolved in the development version, should probably go to CRAN though

[varelasebastian]

same problem...

[gdente90]

Dear Mosen111, what kind of alternative did you use?
I also have the same problem, and have no idea what to do!

[joaquinsalas]

In my case, I was computing the difference in days between to date variables, e.g.,
variable = d1 - d2. The result, althought looked integer, was class "difftime". Using
variable = as.numeric(variable, units="days")

made missForest happy. I hope this helps.

[meganhazlett]

Hi, your input must be a matrix. The following should work.
x2.imp <- missForest(as.matrix(x2))

[luciewoellenstein44]

I had the same problem, turned out missForest did not like my datetime class for my date variables. I computed them into numeric (which should be easier for any analysis done on them anyway) and that made the error go away. Hope this helps!

[christopherball]

Having just run into the same issue, here's the not-so-obvious but simple cause / solution:

I happen to load my data via read_csv to take advantage of the tibble type. This is the actual culprit. Applying a as.data.frame() ahead of the missForest() call solved my problem. Alternatively, you could simply fallback to the old way of loading data via read.csv().

[WondimuAhmed]

Applying as.data.frame() prior to running missForest solved my problem as well.

[stekhoven]

We intend to move to ranger soon, this will make missForest able to handle tibbles.