Wed, 11 Nov 2015 09:32:43 <[email protected]>
Thomas Anderson <[email protected]> wrote...
On Tue, Nov 10, 2015 at 07:37:27PM +0000, Wm... wrote:
Looking at a diff between the current
advanced-portfolio.scm
and
http://lists.gnucash.org/pipermail/gnucash-devel/attachments/20110110/935
f42b3/attachment-0003.bin
the IRR bits seem fairly self contained.
Agreed; there are only a few places where the code was reshuffled that
I am having trouble with.
But I
blame my inexperience.
I'm struggling too. I don't read Scheme well.
One idea I've had, possible for the weekend, is to compile gnc 2.2.7
which I think the IRR scm was built for just to see what it does. [1]
The thing I wonder about is if an IRR wouldn't immediately result in person
A wanting it to be tweaked this way, B arguing it should be done slightly
differently and C wanting something else included or excluded.
I don't know that that's the case; IRR is a simple calculation without
much tweaking, so long as
you enter correct data on the starting dates. Perhaps you have others
in mind, but the only wrinkle
I can think of is:
(*) Person A wishes to treat Dividend Income separately and use IRR for
only price appreciation;
Person B wants to look at the IRR of total return.
I'm not sure how to handle this or if it is worth ignoring.
[1] at the moment I'm uncertain what the code in the IRR calc does. Is
the Scheme code sufficiently clear to you to say what sums it is doing?
Also, does IRR as an into-the-future calculation or tool for deciding
between prospective investments fit in with the rest of gnc's functionality
generally?
In short, isn't this the kind of thing spreadsheets will always do way
better than we could ever do?
I don't see IRR as an into-the-future calculation nor for deciding
between investments. I thought
that tangent in the original thread discussion was a bit of a
mischaracterization;
noted, what I'm wondering is if you know that isn't what the code does.
certainly
for stock investment accounts this is not the case.
Labouring the point, do you know the code has the same POV as you?
IRR serves roughly the same purpose as "Rate of
Return" currently does in advanced portfolio, but is more intelligent:
adding $5,000 to a $1,000
account today doesn't affect the IRR number but does affect the rate of
return significantly. And
the same is true for less extreme situations, IRR is simply a more
robust accounting of how
investments have previously done.
OK
I hope that makes it clearer why I think this is a useful feature.
Sure. I'm wondering what exactly it does now.
P.S. I'm more inclined to SQL and more recently pandas[2] for analysis.
obviously there is some gap between SQL and pandas and most people but
is it greater or smaller than the gap between Scheme and me or you? :)
[2] http://pandas.pydata.org/ simple and fun
--
Wm...
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