what's wrong with custom function?
 

Function RsGlaso(gama, API, T, Pb)
' Application.Volatile False

Dim Rs As Double, KorekcioniPb As Double
'gama = gas gravity - input testData=0.732
'API = ro [API] - input testData=38
'T - [F] - input testData=180
'Pb - [psi] - input testData=3811

KorekcioniPb = 10 ^ (2.8869 - (14.1811 - 3.3093 * Log(Pb)) ^ 0.5)
'Rs = gama * (((API ^ 0.989) / (T ^ 0.172)) * KorekcioniPb) ^ 1.2255
Rs = gama * (((API ^ 0.989) / (T ^ 0.172)) * KorekcioniPb) ^ 1.2255
RsGlaso = 5
End Function


It works if I type formulas into spreadsheet, but if I defined it as custom
function it returns #VALUE

what's wrong with custom function?
 

It appears to me that you will get a value error when taking the square root
of a negative number.

KorekcioniPb = 10 ^ (2.8869 - (14.1811 - 3.3093 * Log(Pb)) ^ 0.5)

Perhaps re-written as:
KorekcioniPb =
10^((28869 - 100*Sqr(141811 - 33093*Log(Pb))) / 10000)

I think you should get a Value error when Pb is at your test value of 3811
because this causes a negative square root.
Looks to me that Pb should be in the range of 0 - 72.619...

--
Dana DeLouis
Using Windows XP & Office XP
= = = = = = = = = = = = = = = = =


"Juggernnath" wrote in message
...
Function RsGlaso(gama, API, T, Pb)
' Application.Volatile False

Dim Rs As Double, KorekcioniPb As Double
'gama = gas gravity - input testData=0.732
'API = ro [API] - input testData=38
'T - [F] - input testData=180
'Pb - [psi] - input testData=3811

KorekcioniPb = 10 ^ (2.8869 - (14.1811 - 3.3093 * Log(Pb)) ^ 0.5)
'Rs = gama * (((API ^ 0.989) / (T ^ 0.172)) * KorekcioniPb) ^ 1.2255
Rs = gama * (((API ^ 0.989) / (T ^ 0.172)) * KorekcioniPb) ^ 1.2255
RsGlaso = 5
End Function


It works if I type formulas into spreadsheet, but if I defined it as
custom
function it returns #VALUE

what's wrong with custom function?
 

I don't get the #VALUE error unless

API < 0: API ^ 0.989 fails,
T = 0: division by 0 in the Rs= line,
Pb <= 0: Log(Pb) fails,
or
Pb about 72.5: (14.1811 - 3.3093 * Log(Pb)) ^ 0.5 fails.

On the other hand, since you put RsGlaso = 5, the function will, if
it doesn't error, always return 5. That can't be right...

In article ,
"Juggernnath" wrote:

Function RsGlaso(gama, API, T, Pb)
' Application.Volatile False

Dim Rs As Double, KorekcioniPb As Double
'gama = gas gravity - input testData=0.732
'API = ro [API] - input testData=38
'T - [F] - input testData=180
'Pb - [psi] - input testData=3811

KorekcioniPb = 10 ^ (2.8869 - (14.1811 - 3.3093 * Log(Pb)) ^ 0.5)
'Rs = gama * (((API ^ 0.989) / (T ^ 0.172)) * KorekcioniPb) ^ 1.2255
Rs = gama * (((API ^ 0.989) / (T ^ 0.172)) * KorekcioniPb) ^ 1.2255
RsGlaso = 5
End Function


It works if I type formulas into spreadsheet, but if I defined it as custom
function it returns #VALUE

what's wrong with custom function?
 

LOG(3811)=3.5810389
*3.3093=11.850732
14.811-11.850732=2.9602678
SQR(2.9602678 0) = 1.72
I didn't understand if you made calculating mistake or tried to say
something else...
================================================== ==============
"Dana DeLouis" wrote in message
...
It appears to me that you will get a value error when taking the square
root
of a negative number.

KorekcioniPb = 10 ^ (2.8869 - (14.1811 - 3.3093 * Log(Pb)) ^ 0.5)

Perhaps re-written as:
KorekcioniPb =
10^((28869 - 100*Sqr(141811 - 33093*Log(Pb))) / 10000)

I think you should get a Value error when Pb is at your test value of 3811
because this causes a negative square root.
Looks to me that Pb should be in the range of 0 - 72.619...

--
Dana DeLouis
Using Windows XP & Office XP
= = = = = = = = = = = = = = = = =


"Juggernnath" wrote in message
...
Function RsGlaso(gama, API, T, Pb)
' Application.Volatile False

Dim Rs As Double, KorekcioniPb As Double
'gama = gas gravity - input testData=0.732
'API = ro [API] - input testData=38
'T - [F] - input testData=180
'Pb - [psi] - input testData=3811

KorekcioniPb = 10 ^ (2.8869 - (14.1811 - 3.3093 * Log(Pb)) ^ 0.5)
'Rs = gama * (((API ^ 0.989) / (T ^ 0.172)) * KorekcioniPb) ^ 1.2255
Rs = gama * (((API ^ 0.989) / (T ^ 0.172)) * KorekcioniPb) ^ 1.2255
RsGlaso = 5
End Function


It works if I type formulas into spreadsheet, but if I defined it as
custom
function it returns #VALUE

what's wrong with custom function?
 

In VBA, LOG() is the natural log function. In XL, LOG(x) is the log
to base x, with the default being base 10.

If you want log base 10 in VBA, use Log(x)/Log(10)

?Log(3811)/Log(10)
3.58103894877217


In article ,
"Juggernnath" wrote:

LOG(3811)=3.5810389
*3.3093=11.850732
14.811-11.850732=2.9602678
SQR(2.9602678 0) = 1.72
I didn't understand if you made calculating mistake or tried to say
something else...

what's wrong with custom function?
 

Hi. Looks like J.E. caught the problem here. :) Here are some
additional ideas for consideration:

Sub Demo()
'VBA
Debug.Print Log(3811)

Worksheet Function
Debug.Print WorksheetFunction.Log(3811, 10)
Debug.Print WorksheetFunction.Log10(3811)
End Sub

returns...
8.24564690087386
3.58103894877217
3.58103894877217

--
Dana DeLouis
Using Windows XP & Office XP
= = = = = = = = = = = = = = = = =


"Juggernnath" wrote in message
...
LOG(3811)=3.5810389
*3.3093=11.850732
14.811-11.850732=2.9602678
SQR(2.9602678 0) = 1.72

<snip

what's wrong with custom function?
 

Sorry, I thought of something like that, but I was stupid and quickly
checked the function in Worksheet. I didn't know that Log isn't the same
function in Sheet and in VBA.
"Dana DeLouis" wrote in message
...
Hi. Looks like J.E. caught the problem here. :) Here are some
additional ideas for consideration:

Sub Demo()
'VBA
Debug.Print Log(3811)

Worksheet Function
Debug.Print WorksheetFunction.Log(3811, 10)
Debug.Print WorksheetFunction.Log10(3811)
End Sub

returns...
8.24564690087386
3.58103894877217
3.58103894877217

--
Dana DeLouis
Using Windows XP & Office XP
= = = = = = = = = = = = = = = = =


"Juggernnath" wrote in message
...
LOG(3811)=3.5810389
*3.3093=11.850732
14.811-11.850732=2.9602678
SQR(2.9602678 0) = 1.72

<snip

what's wrong with custom function?
 

Thanks, I didn't know that Log isn't the same function in Sheet and in VBA.
"J.E. McGimpsey" wrote in message
...
In VBA, LOG() is the natural log function. In XL, LOG(x) is the log
to base x, with the default being base 10.

If you want log base 10 in VBA, use Log(x)/Log(10)

?Log(3811)/Log(10)
3.58103894877217


In article ,
"Juggernnath" wrote:

LOG(3811)=3.5810389
*3.3093=11.850732
14.811-11.850732=2.9602678
SQR(2.9602678 0) = 1.72
I didn't understand if you made calculating mistake or tried to say
something else...