rsom

Error in apply(mydata, 2, var) : dim(X) must have a positive length

I am facing this error even mydata is not null.How to overcome this error. 

> dim(som_model$codes)
NULL
> som_model$codes
[[1]]
         Monetray     Frequency     Recency
V1   -0.222667452 -0.3524154924  0.04209164
V2   -0.216275559 -0.3538082762  0.21107959
V3   -0.212684685 -0.3474491246  0.43714767
V4   -0.237204286 -0.3659989235  0.61105297
V5   -0.205093463 -0.3229735212  0.79368476
> mydata <- som_model$codes
> wss <- (nrow(mydata)-1)*sum(apply(mydata,2,var))
Error in apply(mydata, 2, var) : dim(X) must have a positive length
> length(mydata)
[1] 1
> mydata
[[1]]
         Monetray     Frequency     Recency
V1   -0.222667452 -0.3524154924  0.04209164
V2   -0.216275559 -0.3538082762  0.21107959

https://www.r-bloggers.com/self-organising-maps-for-customer-segmentation-using-r/

Solution

  • som_model$codes looks like a list with a matrix at index 1. You should be able to access the matrix by using:

    mydata <- som_model$codes[[1]]

    Instead of 

    mydata <- som_model$codes