మూస:Inflation/doc పేజీ సోర్సు చూడండి

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{{Ambox|type = content| text =  This template is '''only capable''' of inflating Consumer Price Index values: staples, workers rent, small service bills (doctor's costs, train tickets).  This template is '''incapable''' of inflating Capital expenses, government expenses, or the personal wealth and expenditure of the rich.  '''Incorrect use of this template would constitute original research. If you yourself do not possess it, please consult someone with economic training before making use of this.'''}}
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This template takes a <code>[[List of country codes|country_code]]</code>, for example, "<code>US</code>" for the [[United States]] or "<code>UK</code>" for [[United Kingdom]], a <code>value</code> in that country's currency, a <code>start_year</code>, and applies to it the country's [[consumer price index|consumer price inflation]] until "recently" or another end year.<ref>How recently depends on how the data set for each country is constructed, and on the internal tables being updated accordingly every January. Some data tables provide inflation data up to December 31, {{#expr:{{CURRENTYEAR}}-1}}, others up to roughly June-July {{#expr:{{CURRENTYEAR}}-1}}, and others yet up to December 31, {{#expr:{{CURRENTYEAR}}-2}}.</ref> For example, this template calls the U.S. inflation table located in the sub-template [[Template:Inflation/US/dataset]] to perform the U.S. calculation. This means that whenever a new year arrives and the inflation tables are updated, all articles using this template have their displayed values updated accordingly.

Alternatively, you can provide a second, optional <code>end_year</code> parameter, and the value will be inflated for the period between the two years, providing a convenient way of getting values from different time periods adjusted around the same date.

== Usage ==
 {{Tlx|Inflation|''country_code''|''value''|''start_year''}}
 {{Tlx|Inflation|''country_code''|''value''|''start_year''|''end_year''}}
 {{Tlx|Inflation|''country_code''|''value''|''start_year''|r{{=}}''decimals''|fmt{{=}}c}}
 {{Tlx|Inflation|''country_code''|''value''|''start_year''|r{{=}}''decimals''|fmt{{=}}eq}}
 {{Tlx|Inflation|''country_code''|''value''|''start_year''|r{{=}}''decimals''|fmt{{=}}eq|cursign{{=}}X}}

The supported countries are listed below, with their '''country_code''' and minimum '''start_year''':

{|class="wikitable sortable"
! ''Country name'' !! <code>country_code</code> !! minimum for <code>start_year</code>
|-
| [[Australia]]{{inflation-fn|AU}}      || align="center" | '''AU''' || align="center" | 1901
|-
| [[Canada]]{{inflation-fn|CA}}         || align="center" | '''CA''' || align="center" | 1916
|-
| [[Germany]]{{inflation-fn|DE}}        || align="center" | '''DE''' || align="center" | 1882
|-
| [[India]]{{inflation-fn|IN}}          || align="center" | '''IN''' || align="center" | 1953
|-
| [[Japan]]{{inflation-fn|JP}}          || align="center" | '''JP''' || align="center" | 1970
|-
| [[United Kingdom]]{{inflation-fn|UK}} || align="center" | '''UK''' || align="center" | 1264
|-
| [[United States]]{{inflation-fn|US}}  || align="center" | '''US''' || align="center" | 1800
|}

=== Parameters ===
* '''country_code''' (parameter 1) can be: AU, CA, DE, UK, US, UKNGDPPC, etc.
* '''value''' (parameter 2) can have commas, but no [[currency symbol]].
* '''start_year''' (parameter 3) depends on years allowed for each country.
* '''end_year''' (parameter 4), if provided, must be higher (later) than '''start_year''', but not higher than the current year, and will default to "recently" if left out;
* '''r='''''digit'' sets the digit in which the value must be rounded, defaulting to "0" if unspecified, i.e., without cents (see [[Template:Inflation#Tips & Tricks|Tips & Tricks]] below for details on how to use this parameter).
* '''fmt=c''' will insert commas into the inflated value.
* '''fmt=eq''' will show an equivalent-to phrase.
* '''cursign=X''' will set the [[currency symbol]] when 'fmt=eq' is used (default: $).

=== Examples ===
* {{Aye}} <code>{{Tlx|Inflation|US|595|1982}}</code> = {{Inflation|US|595|1982}}
* {{Aye}} <code>US&nbsp;$595 (${{Tlx|Inflation|US|595|1982|fmt{{=}}c}} today)</code> = US&nbsp;$595 (${{Inflation|US|595|1982|fmt=c}} today)
* {{Aye}} <code>US&nbsp;$595 ({{Tlx|Inflation|US|595|1982|fmt{{=}}eq}})</code> = US&nbsp;$595 ({{Inflation|US|595|1982|fmt=eq}})
* {{Aye}} <code>{{Tlx|Inflation|US|800|1942|r{{=}}-3|fmt{{=}}eq}}</code> = {{Inflation|US|800|1942|r=-3|fmt=eq}}
* {{Aye}} <code>{{Tlx|Inflation|US|100|2010|2012|r{{=}}2|fmt{{=}}eq}}</code> = {{Inflation|US|100|2010|2012|r=2|fmt=eq}}
* {{Nay}} {{Tlx|Inflation|UK|1|1323|fmt{{=}}eq}} = {{Inflation|UK|1|1323|fmt=eq}}
* {{Aye}} {{Tlx|Inflation|UK|1|1323|fmt{{=}}eq|cursign{{=}}£}} = {{Inflation|UK|1|1323|fmt=eq|cursign=£}}
* {{Aye}} {{Tlx|Inflation|DE|100|2000}} = {{Inflation|DE|100|2000}}

Entering invalid parameters will result in a link to the [[NaN]] article:

* {{Nay}} {{Tlx|Inflation}} = {{Inflation}}
* {{Nay}} {{Tlx|Inflation|abc}} = {{Inflation|abc}}
* {{Nay}} {{Tlx|Inflation|DE|1000000}} = {{Inflation|DE|1000000}}
* {{Nay}} {{Tlx|Inflation|US|1000000|1200|3000}} = {{Inflation|US|1000000|1200|3000}}
* {{Nay}} {{Tlx|Inflation|UK|1000000|2005|2004}} = {{Inflation|UK|1000000|2005|2004}}

=== Tips & Tricks ===
==== Currency conversion ====
This template is currency agnostic, which means it doesn't convert between different currencies. Thus, if you wanted to know how much DM 1,000.00 marks in 1960 are worth nowadays, entering {{Tlx|Inflation|DE|1000|1960|r{{=}}2}} would provide a result (''{{Inflation|DE|1000|1960|r=2}}'') still in marks, not in euros.

Consequently, if you need a result in another currency than the one in which the original value is stated, for now you must do the conversion manually, as in the following example which uses the defined conversion rate of €&nbsp;1 = DM&nbsp;1.95583:

* {{Aye}} <code><nowiki>{{#expr:</nowiki>({{Tlx|Inflation|DE|1000|1960|r{{=}}2}}<nowiki> / 1.95583) round 2}}</nowiki></code> = {{#expr:({{Inflation|DE|1000|1960|r=2}} / 1.95583) round 2}}

A currency conversion template to ease these conversion tasks is planned. This section will be updated accordingly once it's developed.

==== Rounding ====
By default the values are calculated to the unit, as for all but very low values cents are undesirable. You can specify rounding with the {{para|r}} parameter which determines the number of decimals. To obtain cents use {{para|r|2}}, but other values can be used, including negative ones: {{para|r|-3}}, for example, will round to the nearest thousand, {{para|r|-6}} to the nearest million, and so on. It is advisable to avoid excessive precision; even if the start value is known to be exact, the template's result will not be because the inflation index tables are rarely accurate to more than about 1%, and a granularity of whole years is used.

==== Very large results ====
Very large results are expressed in scientific notation ("1.2E+14" instead of "120000000000000") which is normally not desirable. A workaround is to express the value to be inflated with fewer digits, adding a multiplier text such as "trillion" after the result, using the "Show preview" button as many times as needed, changing parameters until the best result is found:

* {{Aye}} <code>${{Tlx|Inflation|US|1000000000000|1900|r{{=}}-11|fmt{{=}}c}}</code> = ${{Inflation|US|1000000000000|1900|r=-11|fmt=c}}
* {{Nay}} <code>${{Tlx|Inflation|US|10000000000000|1900|r{{=}}-12|fmt{{=}}c}}</code> = ${{Inflation|US|10000000000000|1900|r=-12|fmt=c}}
* {{Nay}} <code>${{Tlx|Inflation|US|10000000000|1900|r{{=}}-9|fmt{{=}}c}} '''thousand'''</code> = ${{Inflation|US|10000000000|1900|r=-9|fmt=c}} thousand
* {{Aye}} <code>${{Tlx|Inflation|US|10000000|1900|r{{=}}-6|fmt{{=}}c}} '''million'''</code> = ${{Inflation|US|10000000|1900|r=-6|fmt=c}} million
* {{Aye}} <code>${{Tlx|Inflation|US|10000|1900|r{{=}}-3|fmt{{=}}c}} '''billion'''</code> = ${{Inflation|US|10000|1900|r=-3|fmt=c}} billion
* {{Aye}} <code>${{Tlx|Inflation|US|10|1900|fmt{{=}}c}} '''trillion'''</code> = ${{Inflation|US|10|1900|fmt=c}} trillion

The following section provides an automated way of avoiding this trial and error scenario.

==== Formatprice ====
{{Tlx|Formatprice}} is a template specifically designed to display price values, both big and small, in a readable way. For example, instead of showing the whole of a huge number such as "953,783,409,856.12", it would show it as "{{Formatprice|953783409856.12}}", while small numbers have their cents part appearing as expected, "1234.5" being properly shown as "{{Formatprice|1234.5}}".

* {{Aye}} <code>$<nowiki>{{</nowiki>[[Template:Formatprice|Formatprice]]<nowiki>|</nowiki>{{Tlx|Inflation|US|10000000000000|1900}}<nowiki>}}</nowiki></code> = ${{Formatprice|{{Inflation|US|10000000000000|1900}}}}
* {{Aye}} <code>$<nowiki>{{</nowiki>[[Template:Formatprice|Formatprice]]<nowiki>|</nowiki>{{Tlx|Inflation|US|1000000|1990}}<nowiki>}}</nowiki></code> = ${{Formatprice|{{Inflation|US|1000000|1990}}}}
* {{Aye}} <code>DM <nowiki>{{</nowiki>[[Template:Formatprice|Formatprice]]<nowiki>|</nowiki>{{Tlx|Inflation|DE|1000000|1957|1978}}<nowiki>}}</nowiki></code> = DM {{Formatprice|{{Inflation|DE|1000000|1957|1978}}}}
* {{Aye}} <code>£<nowiki>{{</nowiki>[[Template:Formatprice|Formatprice]]<nowiki>|</nowiki>{{Tlx|Inflation|UK|1000|1323}}<nowiki>}}</nowiki></code> = £{{Formatprice|{{Inflation|UK|1000|1323}}}}

==== Documenting ====
It's a good practice to provide a valid reference for the prices calculated with this template in articles where it's used. The template {{Tl|Inflation-fn|''country''}} was developed to ease this task. It accepts as its single parameter the same country codes used here, and will generate one or more appropriate footnotes. Typically, this is how a piece of text using it looks like:

* <code><nowiki>In 1985 a unit cost on average $1,040. This is {{Inflation|US|1040|1985|fmt{{=}}eq}}}}.{{Inflation-fn|US}}</nowiki></code>

Resulting in this converted code (notice the footnote link at the end):

* In 1985 a unit cost on average $1,040. This is {{Inflation|US|1040|1985|fmt=eq}}.{{Inflation-fn|US}}

The footnote thus generated appears whenever {{Tlx|reflist}} or <code><nowiki><references /></nowiki></code> is used in an article, usually in its "References" section. See below for the live example in this document's own [[Template:Inflation#References|References]] section, or click the above generated footnote to jump to it.

=== Limitations ===
#Currently it isn't possible to "de-inflate" a value to what it would have been in a previous year. If you need this functionality, please request it at the [[Template talk:Inflation|talk page]]. Adding it won't be difficult, but there's no point in doing so before someone actually needs it.
#[[Wikipedia:Template substitution|Substitution]] isn't supported at all. Trying to <code><nowiki>{{subst:</nowiki>[[Template:Inflation|Inflation]]<nowiki>|...}}</nowiki></code> would only result in a long sequence of embedded parser code without any direct benefit. If you need to obtain an inflated price only once, please use the special [[Special:ExpandTemplates|ExpandTemplates]] page then copy the result and paste it at the desired location.

=== Developer Documentation ===
An inflation series represents templates in the following categories:
*Template:Inflation/name
*Template:Inflation/name/dataset
*Template:Inflation/name/startyear
*Template:Inflation/doc/name  (Which is then displayed at Inflation/name/dataset as the documentation, and needs to refer to the original data source)
Modifications need to be made to:
*Template:Inflation-fn

== See also ==
* {{tl|Inflation-fn}}
* {{tl|Formatprice}}
* [[Inflation]]
* [[Consumer price index]]
* [[Harmonised Index of Consumer Prices]]
* [[List of country codes]]
* [[List of circulating currencies]]
* [[United States Consumer Price Index]]
* [[Consumer Price Index (United Kingdom)]]
{{Math templates|conversion}}

== References ==
{{reflist}}

<includeonly>{{#ifeq:{{SUBPAGENAME}}|sandbox | |
<!--Categories below this line, please; interwikis at Wikidata-->
[[Category:Currency conversion templates]]
[[Category:Economics formatting and function templates]]
[[Category:Finance formatting and function templates]]
[[Category:United States economic templates]]

[[de:Vorlage:Inflation/Doku]]
[[fa:الگو:Inflation/توضیحات]]
[[it:Template:Inflazione/man]]
[[ml:ഫലകം:Inflation/doc]]
[[ne:ढाँचा:Inflation/doc]]
[[pl:Szablon:Inflacja/opis]]
[[pt:Predefinição:Inflação]]
}}</includeonly>