;doc: valuation: clarify this section; note a recent change

Note that default valuation commodity is now chosen from the latest
suitable P directive on any date, not just before the valuation date.
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Simon Michael 2020-06-13 12:20:55 -07:00
parent 6211a59144
commit 4e182e651b

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@ -1123,42 +1123,96 @@ $ hledger balance --pivot member acct:.
## Valuation
hledger can show
cost reports, where amounts are converted to their cost or sale amount
at transaction time;
or value reports, where amounts are converted to their market value in
another currency/commodity at a specified date
(using market prices inferred from your transactions, or declared with P directives).
Instead of reporting amounts in their original commodity,
hledger can convert them to:
We call this "valuation", and it is controlled by the `--value=VALUATIONTYPE[,COMMODITY]` option.
It can get a little involved, so we cover all the details below.
But most of the time, all you need to do is use these simpler flags instead:
- cost (or sale amount), using the conversion rate recorded as part of
the transaction
([transaction price](journal.html#transaction-prices)).
- `-B` to convert to cost/sale amount, or
- `-V` to convert to market value in your base currency. Or occasionally,
- `-X COMMODITY` to convert to market value in some other currency.
- value, using the [market prices](#market-prices) in effect on certain date(s).
<!-- These flags are mutually exclusive; if you combine them in a command, the rightmost wins. -->
We call this "valuation", and it is controlled in full by the
`--value=VALUATIONTYPE[,COMMODITY]` option.
But we also provide simpler, Ledger-compatible `-B`/`-V`/`-X` flags,
and usually one of these is all you need:
- `-B` to show cost/sale amount
- `-V` to show market value in your usual base currency
- `-X COMMODITY` to show market value in a specified currency.
### -B: Cost
The `-B/--cost` flag converts amounts to their cost or sale amount at transaction time,
if they have a [transaction price](journal.html#transaction-prices) specified.
(It is equivalent to `--value=cost`.)
### -V: Value
The `-V/--market` flag converts reported amounts to market value in
their *default valuation commodity*, using the [market prices](#market-prices)
in effect on a *default valuation date*. (More on these below.)
The `-V/--market` flag converts amounts to market value in their
default *valuation commodity*, using the
[market prices](#market-prices) in effect on the *valuation date(s)*,
if any. More on those in a minute.
The default valuation commodity is the one referenced in the latest
applicable market price (declared by a P directive, for the source
commodity, dated on or before the valuation date). Typically your P
declarations reference a single base currency, and -V will pick that.
### -X: Market value in specified commodity
The default valuation date is today for single period reports (equivalent to `--value=now`),
or the last day of each subperiod for [multiperiod reports](#report-intervals) (equivalent to `--value=end`).
The `-X/--exchange` option is like `-V` except the desired valuation
currency is specified explicitly.
### Valuation date
For single period reports, if an explicit
[report end date](#report-start-end-date) is specified, that will be
used as the valuation date; otherwise the valuation date is "today".
For [multiperiod reports](#report-intervals), each column is valued on
the last day of its period (displayed in the column heading).
### Market prices
To convert a commodity A to its market value in commodity B, hledger
looks for a suitable market price (exchange rate) in these ways,
in this order of preference:
1. a *declared market price* -
the latest [P directive](journal.html#declaring-market-prices)
on or before the valuation date that declares A's price in B.
2. an *implied market price* -
we look for the latest transaction on or before the valuation date
where A is converted to B,
and use its [transaction price](journal.html#transaction-prices)
(assuming that this is probably close to the market price).
(*since hledger 1.18; experimental*)
3. a *reverse declared market price* -
calculated by inverting a declared market price from B to A.
4. a *reverse implied market price* -
calculated by inverting an implied market price from B to A.
5. an *indirect market price* -
calculated by combining the shortest chain of market prices (any of
the above types) leading from A to B.
Amounts for which no suitable market price is found are not converted.
### Valuation commodity
With `-X COMM`, the valuation commodity is COMM, and hledger tries to
convert all amounts to COMM.
With `-V`, hledger picks a valuation commodity automatically.
Typically your P declarations reference a single base currency, and -V
will use that.
In more detail: for each source commodity A, it chooses a valuation
commodity B based on, in this order of preference:
1. the latest P directive (on any date) declaring a price for A.
Amounts for which no valuation commodity can be identified are not converted.
### Valuation examples
An example:
@ -1190,39 +1244,8 @@ $ hledger -f t.j bal -N euros -V
$103.00 assets:euros
```
### -X: Market value in specified commodity
The `-X/--exchange` option is like `-V`, except it specifies the target commodity you would like to convert to.
(It is equivalent to `--value=now,COMM` or `--value=end,COMM`.)
### Market prices
To convert a commodity A to commodity B, hledger looks for a suitable
market price (exchange rate) in the following ways, in this order of
preference:
1. a *declared market price* - the latest [P directive](journal.html#declaring-market-prices)
specifying the exchange rate from A to B, dated on or before the valuation date.
2. a *transaction-implied market price* - a market price matching the
[transaction price](journal.html#transaction-prices) used in the
latest transaction where A is converted to B,
dated on or before the valuation date.
(*since hledger 1.18; experimental*)
3. a *reverse declared market price* - calculated by inverting a
declared market price from B to A.
4. a *reverse transaction-implied market price* - calculated by
inverting a transaction-implied market price from B to A.
5. an *indirect market price* - calculated by combining the shortest
chain of market prices (any of the above types) leading from A to B.
### --value: Flexible valuation
*(experimental, added 201905)*
`-B`, `-V` and `-X` are special cases of the more general `--value` option:
--value=TYPE[,COMM] TYPE is cost, then, end, now or YYYY-MM-DD.