let data = Frame.ReadCsv("sample.csv", hasHeaders = false, schema = "R1,R2,R3")

use file = File.OpenRead("sample.csv")
using (new StreamReader(file)) ( fun reader ->
    while file.ReadByte() <> 10 do ()
    let data = Frame.ReadCsv(stream=file, schema = "R1,R2,R3", hasHeaders=true)
    //...
)

Row1,Row2,Row3,Row4
1,2,3
a,b,c