Inverse Cosine function problem

[BarryClark]

I have a query in an access 2007 database that returns a numerical value for the cosine of an angle. I need to transform that value into the angle itself but there is no ArcCos function in Access.
I have created a new Module, which I named ArcCOS to do that but when I test it in the Immediate environment, it returns a Compile Error --- Expected Variable or Procedure, not Module.

The code for the Module I created is:

Option Compare Database

Public Function ArcCOS(ByVal nValue As Double, Optional fRadians As Boolean = True) As Double
Const PI As Double = 3.14159265359
ArcCOS = -Atn(nValue / Sqr(1 - nValue * nValue)) + PI / 2
If fRadians = False Then ArcCOS = ArcCOS * (PI / 180)
End Function

Can anyone tell me what I have got wrong?

 

[MarkK]

Hello and welcome to the forum.
Is your nValue < 1? An nValue greater than 1 will cause you to pass a negative value to the Sqr() function, which then fails.
Probably you need to check for, and do the conversion to, radians before calculating your ACOS.
Mark

 

[BarryClark]

Everything is computed in radians and the returned value from the query calculation is less than 1. To test the module in the immediate environment, the entry I made set a value for the cosine as 0.75 as follows: ?ArcCOS(0.75)

 

[MarkK]

Barry, I can't reproduce your error. For me the function works if I type this ...

? ArcCOS(0.75)

... in the immediate pane. It fails, as I mentioned above, if I do this ...

? arccos(30, False)

Does the compiler highlight a particular line in your code?

 

[WayneRyan]

Barry,

Your module and function can't have the same name.

hth,
Wayne

 

[BarryClark]

The function seems to compile properly if I go through the Debug/Compile process, but when I test it in the immediate environment it fails. There is no indication of a failure in any specific line of code. There is just a Microsoft Visual Basic box comes up with:

Compile Error:

Expected Variable or Procedure, not Module

and OK and Help buttons

The help button provides the following response:

Expected variable or procedure, not module

There is no variable or procedure by this name in the current scope , but there is a module by this name. This error has the following cause and solution:

• The name of a module is used as a variable or procedure. Check the spelling of the variable or procedure name, and make sure the name you want to refer to isn't private to another module. A module name can be a qualifier, but can't stand alone.

For additional information, select the item in question and press F1 (in Windows) or HELP (on the Macintosh).
ofm

F1 just takes me to a a Help display of the Project Explorer hierarchy.

 

[MarkK]

I think Wayne got it there Barry. Rename the module or the function and retry.

 

[BarryClark]

Thanks to both of you -- I changed the function to ACOS and that solved the problem.

I knew I was doing something stupid...............

This was the first time I had directly coded any kind function, so it was a real learning experience and I really appreciate your help.

 

[MarkK]

Well, nicely done for a first time. To me it's the breakthroughs in learning that are the most fun.
Cheers,