Wish Add the Round2 method in B4i

[klaus]

In B4A and B4J we have the Round2(Number As Double, DecimalPlaces As Int)
Can you please add in B4i, if Is it possible.

Currently I use this workaround:

Private Sub Round2(Number As Double, DecimalPlaces As Int) As Double
    Private str As String
    
    str = NumberFormat(Number, 1, DecimalPlaces)
    Number = str
    Return Number
End Sub

 

[Erel]

Why do you need it?

In most cases it is a mistake to use Round2.

 

[klaus]

I use it in the xChart class to compare Doubles limited to 14 decimal numbers to calculate logarithmic scales.

 

[Erel]

I would have used something like for comparisons:

Public epsilon As Double = 0.01 'constant

'compare
If Abs(d1 - d2) < epsilon Then 'they are "equal"

Much simpler than the implementation of Round2 which is:

Dim shift As Double = Power(10, DecimalPlaces)
Return Round(Number * shift) / shift

It was a mistake to add it to the core library. Its purpose was similar to NumberFormat and NumberFormat is the correct approach for conversation of numbers to strings.