On Tue, Oct 7, 2014 at 4:23 PM, Simon Michael <[email protected]> wrote:
> On 10/7/14 10:03 AM, Nathan Grigg wrote:
>
>> I wonder if inferring like Ledger works in all cases though;
>>>>> consider this case:
>>>>>
>>>>> Assets:Fidelity:Fund 11.27534 FUND {1.2357 USD}
>>>>> Assets:Fidelity:Cash -13.93 USD
>>>>>
>>>>> The precise cash amount is 13.932937638 USD.
>>>>> How many digits should this use?
>>>>>
>>>>
>>>> Ledger would infer 2 digits of precision for USD and 5 for FUND.
>>>> The price portion does not affect precision. Ledger also has a D
>>>> directive to specify the minimum precision per currency.
>>>>
>>>
>>> I'm not sure what that means... there is no need for any precision on
>>> units of FUND, the balance amount of that leg is in USD calculated as
>>> 11.27534 x 1.2357. In USD. The balance residual is 11.27534 x 1.2357 +
>>> -13.93. The only precision that matters is that of USD.
>>>
>>> Does it use the precision inferred on units of FUND in any way?
>>> If so, how?
>>>
>>
>> In Ledger, the precision is not per-transaction, but file-wide. (Because
>> Ledger process the file in one pass, this means that the precision may
>> increase, but never decrease, as it processes the file.) So Ledger would
>> infer from this posting that FUND should always be measured and
>> displayed to 5 digits of precision (or at least from now on).
>>
>
> More data points for this intricate topic. hledger's per-commodity display
> precisions are also file-wide, but here are some differences from Ledger:
>
> 1 the whole file is processed first, then the precisions are selected.
> So a high-precision amount at the end can set the precision for all
> (actually, isn't that true for Ledger too ? My testing says yes).
>
That's great. IMO it's a bad idea to change whatever value is derived as
the system parses the file. Ordering should never matter, even for
precision or formatting.
2 the D directive itself does not influence the precision, but
> hledger applies the D commodity to any commodity-less amounts,
> in which case that adjusted amount will influence the precision
> (see example at http://hledger.org/manual#default-commodity).
>
> 3 price amounts do not influence the precision, like Ledger... but they
> can be used to balance an amountless posting, and that amount does
> get displayed with the price's original full precision. This is how
> hledger does better in your "Weird things happening" case 1:
>
> D 1.00 USD
> 2014-01-01 Test
> assets 1 CAD @ 1.005 USD
> liabilities
> 2014-01-02 Test
> assets 1 CAD @ 1.005 USD
> liabilities
>
> $ hledger -f tt.j reg liabilities -w66
> 2014/01/01 Test liabilities -1.005 USD -1.005 USD
> 2014/01/02 Test liabilities -1.005 USD -2.010 USD
>
> But I see it still does not influence the canonical precision in
> this case, which looks weird and should probably be fixed:
>
> D 1.00 USD
> 2014-01-01 Test
> assets 1 CAD @ 1.00500 USD
> liabilities
> 2014-01-02 Test
> assets 1 CAD @ 1.005 USD
> liabilities
>
> $ hledger -f tt.j reg liabilities -w66
> 2014/01/01 Test liabilities -1.00500 USD -1.00500 USD
> 2014/01/02 Test liabilities -1.005 USD -2.01000 USD
>
What do you do about the display precision when you have a mix of
transactions with differing precisions?
On Tue, Oct 7, 2014 at 4:37 PM, Simon Michael <[email protected]> wrote:
> I'm not following this interesting discussion in every detail, so I'm not
> sure if this can help any part of this problem space, but just in case:
> Have you considered or already implemented hledger's approach for balancing
> transactions, which is based on display precision ? Ie amounts are
> considered to balance if their sum appears to be zero when it's rendered
> using the canonical display precision. This seems to fit user expectations
> well.
>
How do you define the canonical display precision?
You mean the precision derived from the legs that have a simple explicit
amount?
--
---
You received this message because you are subscribed to the Google Groups
"Ledger" group.
To unsubscribe from this group and stop receiving emails from it, send an email
to [email protected].
For more options, visit https://groups.google.com/d/optout.
