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Rotation Forest Error Message

5 messages · Sparks, John, Abby Spurdle, Rasmus Liland

Sparks, John
# 
Hi R Helpers,

I wanted to try the rotationForest package.

I pointed it at my data set and got the error message "Error in if (K >= ncol(x)) stop("K should not be greater than or equal to the number of columns in x") :
  argument is of length zero'.

My dataset has 3688 obs. of  111 variables.

Would a quick adjustment to the default value of K resolve this?

If anybody with more experience with the package than me has a general suggestion I would appreciate it.

--John Spaarks
Abby Spurdle
# 
Note that I'm not familiar with this package or the method.
Also note that you haven't told anyone what function you're using, or
what your call was.

I'm assuming that you're using the rotationForest() function.
According to its help page, the default is:

    K = round(ncol(x)/3, 0)

There's no reason why the default K value should be higher than the
number of columns, unless:
(1) There's a bug with the package; or
(2) There's a problem with your input.

I note that the package is only version 0.1.3, so a bug is not out of
the question.
Also, I'm a little surprised the author didn't use integer division:

    K = ncol (x) %/% 3

You could just set K to the above value, and see what happens...
On Fri, Aug 21, 2020 at 1:06 PM Sparks, John <jspark4 at uic.edu> wrote:
Abby Spurdle
# 
Just re-read your question and realized I misread the error message.
The argument is of zero length.

But the conclusion is the same, either a bug in the package, or a
problem with your input.
On Fri, Aug 21, 2020 at 4:16 PM Abby Spurdle <spurdle.a at gmail.com> wrote:
Rasmus Liland
#
On 2020-08-21 16:22 +1200, Abby Spurdle wrote:
| On Fri, Aug 21, 2020 at 4:16 PM Abby Spurdle <spurdle.a at gmail.com> wrote:
| | On Fri, Aug 21, 2020 at 1:06 PM Sparks, John <jspark4 at uic.edu> wrote:
| | |
| | | Hi R Helpers,
| | |
| | | I wanted to try the rotationForest 
| | | package.
| | |
| | | I pointed it at my data set and 
| | | got the error message "Error in if 
| | | (K >= ncol(x)) stop("K should not 
| | | be greater than or equal to the 
| | | number of columns in x") :
| | |   argument is of length zero'.
| | |
| | | My dataset has 3688 obs. of  111 variables.
| | |
| | | Would a quick adjustment to the 
| | | default value of K resolve this?
| | |
| | | If anybody with more experience 
| | | with the package than me has a 
| | | general suggestion I would 
| | | appreciate it.
| |
| | Note that I'm not familiar with this 
| | package or the method.  Also note 
| | that you haven't told anyone what 
| | function you're using, or what your 
| | call was.
| |
| | I'm assuming that you're using the 
| | rotationForest() function.  
| | According to its help page, the 
| | default is:
| |
| |     K = round(ncol(x)/3, 0)
| |
| | There's no reason why the default K 
| | value should be higher than the 
| | number of columns, unless:
| | (1) There's a bug with the package; or
| | (2) There's a problem with your input.
| |
| | I note that the package is only 
| | version 0.1.3, so a bug is not out 
| | of the question.  Also, I'm a little 
| | surprised the author didn't use 
| | integer division:
| |
| |     K = ncol(x) %/% 3
| |
| | You could just set K to the above 
| | value, and see what happens...
| 
| Just re-read your question and 
| realized I misread the error message.  
| The argument is of zero length.
| 
| But the conclusion is the same, either 
| a bug in the package, or a problem 
| with your input.

Dear John,

check to see if your columns only has 
numbers in them like the *de jure* iris 
dataset used in the example in 
?rotationForest::rotationForest.

	idx <- 1:100
	idx.new <- which(!(1:nrow(iris) %in% idx))
	y <- as.factor(ifelse(iris$Species[idx]=="setosa", 0, 1))
	x <- iris[idx, -5]
	newdata <- iris[idx.new, -5]
	K <- ncol(x) %/% 3
	L <- 100
	rF <-
	  rotationForest::rotationForest(
	    x=x,
	    y=y,
	    K=K,
	    L=L)
	predict(object=rF, newdata=newdata)

Best,
Rasmus
Sparks, John
# 
Thanks Abby and Rasumus.

I like to leave the solution on this list for the next potential person.

I had failed to realize that this package doesn't use one of the formula forms.  So my call of


RotFor2000<-rotationForest(up~.,data=modeldata)

is what caused the error.

After converting to the appropriate form


x<-subset(modeldata,select=-c(up))
y<-modeldata$up
tic()
RotFor2000<-rotationForest(x,y)
toc()

It ran just fine.

Thanks again.
--John Sparks