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Answer 1

+1 A:

You could use this library that duplicates excel functions in f#

It has PV which is present value. I have used it once or twice. Just drop it in and add the reference.

Gratzy 2009-09-24 14:10:34

hmmm seems kind of risky relying on a CTP language but I think I'd rather do that than reference the Microsoft.VisualBasic library

Dave 2009-09-24 14:25:00

Exactly, when I've used it, it was to avoid excel automation and referencing Excel

Gratzy 2009-09-24 14:26:51

The "NotStandAlone" version is almost 1 meg... almost tempted to just snag the PV function from Reflector, but I'll give this a shot

Dave 2009-09-24 14:40:50

I prefer JDunkerley's solution - I'd rather add a 2 line function to my code rather than reference a whole assembly.

Tom Bushell 2009-09-24 16:11:03

@Dave - -2 ( -1 because I don't agree, and another -1 because I'm a clueless SO noob and accidentally upvoted your comment, and can't undo it. Doh! ;-) Seriously, there's some good stuff in the VB libraries (Shapes, for example). I think it's short sighted to not take advantage because of anti-VB snobbery.

Tom Bushell 2009-09-24 16:19:27

@Tom Bushell I agree in this case if the function is accurate however the library also offers other functions like YTM which is much more difficult to replicate and was what I needed at the time.

Gratzy 2009-09-24 16:20:00

@Tom you've twisted my arm, I'll just use it.

Dave 2009-09-24 17:55:15

So you suggest using a one-man-band unsupported library from Code Galleries, just to avoid using a fully supported core library from the .NET framework? And this has received upvotes? Stack Overflow has blown a fuse. (Using it to get YTM might make sense but that wasn't the question in this case.)

MarkJ 2009-09-25 11:19:07

@MarkJ I'm not suggesting he doesn't use Microsoft.VisualBasic I simply pointed him to an alternative. Unless I'm mistaken I believe that was what he was asking for. I was pointed to that library myself from a similar question I posted.

Gratzy 2009-09-25 12:44:31

Question was " Is this [avoiding Microsoft.VisualBasic] something that is commonly done, or should I explore further options". So if you point him to another library, you're implicitly advising removing Microsoft.VisualBasic. Or that's how I read it anyway.

MarkJ 2009-09-26 07:14:35

Answer 2

+3 A:

Pretty straight forward to replicate in C#

    public static double PV(double Rate, int nPer, double Pmt, double FV, bool Type)
    {
        double ann = Math.Pow(1 + Rate, nPer);
        return -(FV + Pmt * (1 + (Type ? Rate : 0)) * ((ann - 1) / Rate)) / ann;
    }

Just a re-arrangement of the formula Microsoft provides.

JDunkerley 2009-09-24 14:27:34

It's almost a rearrangement of Microsoft's formula, except when rate=0. That's when your version divides by zero, and VB6 and Microsoft.VisualBasic return `-fv -(pmt*nper)`. There are pitfalls even in coding up a formula from a webpage. This reinforces my answer - for pity's sake just **use Microsoft.VisualBasic** and move on to implement something other functionality for the poor old users.

MarkJ 2009-09-25 08:08:23

Answer 3

+4 A:

The use of Microsoft.VisualBasic from C# and VB.NET has been discussed thoroughly under this question. The Microsoft.VisualBasic namespace is fully supported, and will be around as long as .Net is around. There's no reason to avoid it.

EDIT: It's telling that at the time of typing, the other answers for this question are an incorrect reimplementation of the function, and a one-man-band unsupported library from Code Galleries. Come on guys, it would take a real major event for Microsoft to drop the financial functions from VB.

It's a different story for Microsoft.VisualBasic.Compatibility, which is exclusively for use by the VB6 upgrade wizard, may be removed in future versions, and should not be used for new development. There would be some advantages in removing references to this, but personally I'd be sure to achieve a fully working port first.

MarkJ 2009-09-24 16:45:39

Agree 100% with this. Where does this reluctance to use Microsoft's supported library come from? Is it just the "ewwww... it says VB" mentality? WTF? Microsoft wrote VB6, C#, and then provided (for free) the Microsoft.VisualBasic namespace for JUST THIS PURPOSE. And still people hesitate to use it. Whatever--Take your chances with some other "non-VB, therefore better" option.

JeffK 2009-10-01 19:01:13

Just to add: At the end of the day, it's all IL. I can write stuff in C#, Visual Basic.NET, IronPython and Boo and throw it all into the Blender (=compilers) and retrieve IL that doesn't know what it was before.

Michael Stum 2010-03-22 20:34:41

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PV Function and Porting VB6 to C#

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