vw: unrecognised option '--csv'

[Abinash-bit]

I was going through the Command Line for CSV Dataset in tutorials , in the tutorials page it is stated to download the iris.csv , after that it is stated to train the csv dataset using a command vw --csv -d iris.csv --csv_separator "," --csv_header "_tag,Sepal|Length,Sepal|Width,Petal|Length,Petal|Width,_label" --csv_ns_value Sepal:1,Petal:1 --named_labels setosa,versicolor,virginica --oaa 3 -f model.vw

after entering this command in the command line i get an error :
vw: unrecognised option '--csv