Apparent F#/BCL floating point bug

Question

The following is in FSI:

> System.Math.Round(0.2916, 2);;
val it : float = 0.29
> it * 100.;;
val it : float = 29.0
> int it;;
val it : int = 28
         


        

Answer 1

You can change the F# FSI Pretty Printer like Matlab "format long"

fsi.AddPrinter( fun (x:float) -> sprintf "%26.16e" x);;

FSI output

System.Math.Round( 0.2916, 2)   //  2.8999999999999998e-001

1./3.                           // 3.3333333333333331e-001