reports and prices [Patch] reworked advanced-portfolio.scm

[Mike Alexander]

--On February 20, 2006 9:15:05 AM -0800 Andrew Sackville-West 
<andrew at farwestbilliards.com> wrote:

>> One thing I would add to the discussion is to point out that the
>> pricedb is used for two things in this report (and elsewhere).  It
>> contains prices in some currency for the commodities (stocks, bonds,
>> etc.) that are being reported on and it also contains exchange rates
>> used for converting amounts from one currency to another.  The
>> report  can infer the first of these from the transactions, but not
>> the latter.  It really needs the pricedb for that.
>
> Yeah, that's definitely a problem. There needs to bhe another
> exchange-fn, one that doesn't rely on pricedb. And we probably need to
> create BOTH of them in the report simultaneously because we can't know
> which "type" of price data we're going to get in advance. 1) for when
> the pricedb is our source and 2) for when the txn is the source. The
> question is, how can we get currency exchange data? Can we rely on
> there being exchange data if someone is working in multiple
> currencies?

I think you have to rely on that.  I can't think of any other way to 
get the exchange rates, unless a whole new way of storing them is 
invented outside the pricedb.  Generally there aren't enough 
multiple-currency transactions to be useful and they would be hard to 
find.

        Mike