Build a k-fold cross validation splitter, respecting (never splitting) groupingColumn.

Build a k-fold cross validation splitter, respecting (never splitting) groupingColumn.

makekWayCrossValidationGroupedByColumn(groupingColumnName)

Arguments

groupingColumnName	name of column to group by.

Value

splitting function in the sense of vtreat::buildEvalSets.

Examples

d <- data.frame(y=sin(1:100))
d$group <- floor(seq_len(nrow(d))/5)
splitter <- makekWayCrossValidationGroupedByColumn('group')
split <- splitter(nrow(d),5,d,d$y)
d$splitLabel <- vtreat::getSplitPlanAppLabels(nrow(d),split)
rowSums(table(d$group,d$splitLabel)>0)
#>  0  1  2  3  4  5  6  7  8  9 10 11 12 13 14 15 16 17 18 19 20 
#>  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1