Melt & Cast using R in Spotfire

I'm trying to do a simple melt and cast operation using R in spotfire.

Unfortunately the resulting data table does contain by date values but the comlumn with values is empty.

Data_table.m<-melt(Data_table,id="Date", measure="VALUE")

Data_table.c<-reshape::cast(Data_table.m, Date ~ variable, mean)

So Data_table.c does contain the values in the Date column but not in the variable column.

(1) Answer