Warning is produced when running in parallel

[mmahmoudian]

The following warning is thrown when the code is run in parallel.

1: In `[<-.data.frame`(`*tmp*`, , tmp.columns.to.zscore, value = list( :
  provided 114 variables to replace 25 variables

The issue is that in some unlucky cases there are only one column left while we are binning the columns to send to each CPU core. In those cases, selection of columns from a matrix object does not return a table but rather a numeric vector. This means that on the line 677 of the following chuck, we are sending a vector to our func.zscore function rather than a matrix.

sivs/R/sivs.R

Lines 665 to 678 in 7e629e2

	tmp.zscore.res <- foreach::foreach(i = 1:length(tmp.bins),
	.inorder = TRUE,
	.combine = cbind.data.frame) %mydo% {
	# if user wants to have progressbar
	if(progressbar){
	# increment the progressbar
	setTxtProgressBar(pb = pb, value = getTxtProgressBar(pb) + 1)
	}
	lapply(x[, tmp.bins[[i]]], func.zscore)
	}

The x[, tmp.bins[[i]]] in line 677 of the chunk above is equivalent of:

base::getElement(object = x, name = tmp.bins[[i]])

The solution is pretty obvious, using base::subset(), although I think it will add some overhead on the runtime of the code. But because it is run only once per each SIVS run, it is pretty okay. The fix will come in PR #8.