Provide examples in documentation

[Nelson-Gon]

I have discovered this package and being a new user went straight to the docs to see how to use each of these functions. I tried as.gpuMatrix and naturally would think as..... is converting whatever I give it to a gpuMatrix so I tried:

gpuR::as.gpuMatrix(c(1:3),"vector")

This results in:

Error in (function (classes, fdef, mtable) :
unable to find an inherited method for function ‘as.gpuMatrix’ for signature ‘"integer"’

I think this has to do with the package being written in s4 while I obviously used s3 like programming. However, a new user will not know what is going on and one would have expected a few examples of how to use these functions. The help docs for most of the functions are missing examples and the vignette(that I read first) also doesn't really provide enough guidance.