0.000001403012501 --> 1.40301e-06

[JumpyNET]

1)

How can I round a variable of the type Double to six most significant numbers (not six decimals)?

0.000001403012501 --> 0.00000140301

1403012501 --> 1403010000

 

2)

How can I convert a variable of the type Double to string in exponential form - even if the exponent would be something very small?

0.00000140301 --> "1.40301e-06"

 

3)

I bet you could do the thing in the first question at same time you do the thing in the second question, but I want to keep those procedures separate.

Edited March 6, 2008 by JumpyNET

[PlausiblyDamp]

Second one first...

Dim d As Double = 0.00000140301
MessageBox.Show(d.ToString("E3"))
MessageBox.Show(d.ToString("E4"))
MessageBox.Show(d.ToString("E5"))

will have to look into the other one...

[JumpyNET]

Thank you PlausiblyDamp for helping me with the exponent question.

 

I solved the rounding to significant figures myself. I just love programming because there is so much math involved. :D

 

Here is the solution:

   Function SigRnd(ByVal d As Double, ByVal n As Integer) As Double
       Dim RetVal As Double = 0

       If d <> 0 Then
           Dim FirsSignicantPos As Integer = Math.Floor(Math.Log10(Math.Abs(d)))
           Dim RoundingPos As Integer = FirsSignicantPos - (n - 1)
           Dim NonSignificantPart As Double = d Mod (10 ^ RoundingPos)
           RetVal = (d - NonSignificantPart)
       End If

       Return RetVal
   End Function

Edited March 10, 2008 by JumpyNET