Wie deklariert man Variablen innerhalb der Excel-Funktion?

Question

Aktualisierter Beitrag

Ich habe den Code wie geändert.

Option Explicit 
Public Function Isokinectic(streamVelocity As Double, sampleVelocity As Double, probeDiameter As Double, density As Double, particleDiameter As Double, viscosity As Double) 

     Dim s As Double 
     Dim stk_coefficent As Double 
     Dim stk As Double 
     Dim d As Double 

     s = ((0.16 * 10^-4)/particleDiameter) + 1 
     stk_coefficent = (1/(18 * viscosity)) * density * particleDiameter * particleDiameter * s 
     stk = (streamVelocity/probeDiameter) * stk_coefficent 
     d = 1 + (2 + 0.62 * (sampleVelocity/streamVelocity)) * stk 
     Isokinectic = 1 + ((streamVelocity/sampleVelocity) - 1) * (1 - 1/(d)) 

End Function 

Aber es funktioniert nicht. Wenn Sie jedoch den Unterbefehl MAIN() hinzufügen, so. Es klappt.

Option Explicit 
Function Isokinectic(streamVelocity As Double, sampleVelocity As Double, probeDiameter As Double, density As Double, particleDiameter As Double, viscosity As Double) 

     Dim s As Double 
     Dim stk_coefficent As Double 
     Dim stk As Double 
     Dim d As Double 

     s = ((0.16 * 10^-4)/particleDiameter) + 1 
     stk_coefficent = (1/(18 * viscosity)) * density * particleDiameter * particleDiameter * s 
     stk = (streamVelocity/probeDiameter) * stk_coefficent 
     d = 1 + (2 + 0.62 * (sampleVelocity/streamVelocity)) * stk 
     Isokinectic = 1 + ((streamVelocity/sampleVelocity) - 1) * (1 - 1/(d)) 

End Function 

Sub MAIN() 
    MsgBox Isokinectic(0.1, 0.2, 0.3, 0.4, 0.5, 0.6) 
End Sub 

Original-Beitrag:

Ich habe versucht, eine Gleichung in Excel-Funktion zu codieren. Aber ich habe #value

Function Isokinectic(streamVelocity As Double, sampleVelocity As Double, probeDiameter As Double, density As Double, particleDiamter As Double, visocity As Double) 

     Dim s As Double 
     Dim stk_coefficent As Double 
     Dim stk As Double 
     Dim d As Double 

     s = (0.16 * 10^ - 4/particleDiameter) + 1 

     stk_coefficent = (1/(18 * viscosity)) * density * particleDiamter * particleDiameter * s 

     stk = (streamVelocity/probeDiameter) * stk_coefficent 

     d = 1 + (2 + 0.62 * (sampleVelocity/streamVelocity)) * stk 

     Isokinectic = 1 + ((streamVelocity/sampleVelocity) - 1) * (1 - 1/(1 + d)) 

     End Function 

Alles, was ich in diesem Code falsch gemacht?

Answer 1

Mit einer wenig Bereinigung:

Option Explicit 
Function Isokinectic(streamVelocity As Double, sampleVelocity As Double, probeDiameter As Double, density As Double, particleDiameter As Double, viscosity As Double) 

     Dim s As Double 
     Dim stk_coefficent As Double 
     Dim stk As Double 
     Dim d As Double 

     s = ((0.16 * 10^-4)/particleDiameter) + 1 
     stk_coefficent = (1/(18 * viscosity)) * density * particleDiameter * particleDiameter * s 
     stk = (streamVelocity/probeDiameter) * stk_coefficent 
     d = 1 + (2 + 0.62 * (sampleVelocity/streamVelocity)) * stk 
     Isokinectic = 1 + ((streamVelocity/sampleVelocity) - 1) * (1 - 1/(1 + d)) 

End Function 

Sub MAIN() 
    MsgBox Isokinectic(0.1, 0.2, 0.3, 0.4, 0.5, 0.6) 
End Sub 

Answer 2

In Ihrem Original-Beitrag von Ihnen s berechnet, d, stk aber in keinem wo in späterem Zeitpunkt Sie den Wert für die Geschwindigkeit bekommen & andere, ist Grund für den Wert Fehler. Da mit einer Unterroutine, wie Sie Value in Formel setzen, es funktioniert, schreiben Sie bitte diese Befehlszeile in Funktion Ihre Funktion wird funktionieren, vergessen Sie nicht, Wert für Velocity aus Zellen zu übergeben.