Template:Val

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This template is used to easily present values in scientific notation, including uncertainty and/or units, as prescribed by Wikipedia's Manual of Style.

Introduction

Val specializes in numeric values, especially those with scientific notations, uncertainty notations, and those with measurement values with physical units. Because these expressions are covered by the Manual of Style, Val provides the stylized output for you, and keeps them from wrapping across lines.

Express a numeral:

• {{val|123456.78901}} → value, formatted with gaps: , or with |fmt=commas →
• {{val|number|number}} → value ± uncertainty, like
• {{val|number|Template:HilitenumberTemplate:Hilite}} → value(uncertainty), like
• {{val|number|number|number}} →value Template:Su like

Express a measurement value: . The m2 is a "unit code" that Val uses to look up the link to the unit's article, and the formatting of the unit symbol. Val links the units to the page it has on file for them. See {{Val/list}}.

There are a large number of unit codes that Val understands and keeps "up to code". A unit code is the just abbreviated unit name, but these can get quite involved for a compound or composite unit, with "multipliers" or "dividers". See Module:Val/units.

Some unit-code flexibility is provided by having four parameters to work the unit-code system: whether to link one or not, (see Overlinking), and whether to link the numerator or denominator of a unit ratio separately.

• {{val|number|ul=unit code}} → number symbol, such as
• {{val|number|u=unit code}} → number symbol, such as
• {{val|number|u=unit code|uTemplate:Hilitel=unit code}} → number symbolTemplate:Hilitesymbol, such as
• {{val|number|ul=unit code|uTemplate:Hilite=unit code}} → number symbolTemplate:Hilitesymbol, such as

To bypass the unit code system, if |u= does not recognize your unit code, it will accept any wikitext and render it as usual.

See Module:Val/units for how to add units to the unit code system.

Sometimes a number and unit code is not enough. A prefix or suffix are also available, |p= and |s=.

See {{val/testcases}} to learn the val parameters by an example. It is comprehensive, and there are over 100 examples.

Arguments

For more details on this topic, see Help:Template#Parameters.

Val takes three unnamed parameters. The first is always the numeric value. When the second and third are numbers they become the various uncertainty notations, but the second unnamed parameter can also serve to grammatically join the first and third numbers.

Val clears surrounding spaces in its unnamed parameters.

1st or |1=	A number. Can be in decimal point notation or in e notation. This number is the basis of the Val formatting.                    (adds the zero)                     (displays the plus)                     (replaces the hyphen-minus with a minus sign)                (E notation)
|fmt=	By default, numbers are formatted with gaps separating groups of three digits in both integer and fractional part. However, by default, four-digit integers are not formatted; use |fmt=gaps to force gaps. Use |fmt=commas to delimit the integer part of the number with commas. Use |fmt=none for no formatting (no gaps or commas).
|end=	Put something at the end of the main number (before anything else that might follow).
2nd or |2=	Uncertainty in either format. A conjunction to join two numbers. Useful for ranges, grammatical output, etc. Note that for dashes or x's, the various kinds all obtain one properly styled output.
3rd or |3=	Asymmetric uncertainty.
|errend= or |+errend= and |-errend=	Appends something after an uncertainty.
|u= or |ul=	The unit code. Val adds a space and the unit. |ul= Link the unit. |u= Don't link the unit. Also accepts wiki markup in lieu of a unit code.
|up= or |upl=	A unit code, but instead of a space Val adds a slash and the unit, a "per" unit (the denominator), to form a ratio. |upl= Link the per unit. |up= Don't link the per unit. The ratio can be of two unit codes, or a prefix and a unit code. Val will add parentheses to disambiguate, if a unit code has a dot or a slash.
|p=	Prefix the entire Val expression. Non-spaced, but accepts markup.
|s=	Suffix the entire Val expression. Non-spaced, but accepts markup.
|e=	Exponent. Val alternatively accepts e notation in the first parameter; these are mutually exclusive (see "1st" argument above).
|long scale=	Usually a unit is the short ton and billion means . But there are long versions of these units and others. Use |long scale=on to assign your unit to the long scale instead. The unit code's link will change and it will sort differently in tables. "See Long and short scales".
|nocategory=	If set to any value, errors in the use of this template will not cause the page to be added to the Pages with incorrect formatting templates use category. This is useful for documentation and test pages that do not need to be fixed.

Errors

There is strict checking on the validity of arguments; any incorrect use will result in an error. Pages that contain incorrect use of this template will show up on Category:Pages with incorrect formatting templates use.

Val checks for unsupported parameters and gives a relatively subtle warning if found. See tracking category to track any of these improper usages on existing on the wiki. Hold the mouse over "warning" to see details. Here is what warnings look like:

• {{val|1.23|exp=6|u=m/s}} →
• {{val|1.23|us=kbit/s}} →
• {{val|1.23|.05|.04|.03|u=m/s}} →

Format of numbers

{{Val}} produces formatting compliant with Wikipedia's Manual of Style.

The MOS recommends that numbers either be delimited using thin spaces either side of the decimal, or commas to the left and no delimiters to the right. Articles should be consistent with respect to the style of delimiting. The template defaults to the former style, this can be adjusted using |fmt= (see above).

Sorting

For more details on this topic, see Help:Sortable tables.

The sort key for each sortable unit is visible at Template:Val/list.

Here is a live example showing the minimal markup for a sortable table:

{| class="wikitable sortable floatright" summary="Val sorting test" |+ Click to sort ↓ |- ! Val sort test ! In base unit ! {{nobold|1=(unsort)}} |- | {{val|3|ul= Mm }} | style="text-align:right" | {{val|3000000|u=m}} | style="text-align:right; font-size:small;" | {{random number|100|1|67}} |- | {{val|4e6|ul= m }} | style="text-align:right" | {{val|4000000|u=m}} | style="text-align:right; font-size:small;" | {{random number|100|3|67}} |- | {{val|1|ul= km }} | style="text-align:right" | {{val|1000|u=m}} | style="text-align:right; font-size:small;" | {{random number|100|5|67}} |- | {{val|5e3|u= m }} | style="text-align:right" | {{val|5000|u=m}} | style="text-align:right; font-size:small;" | {{random number|100|7|67}} |- | {{val|2|u= m }} | style="text-align:right" | {{val|2|u=m}} | style="text-align:right; font-size:small;" | {{random number|100|11|67}} |} |}

Click to sort ↓ Val sort test In base unit (unsort) Template:Random number Template:Random number Template:Random number Template:Random number Template:Random number

A sort value relates to a Val expression as follows.

1. The numeric value is a starting point.
2. If the unit has an SI Prefix, that order of magnitude is applied.
3. The value of the unit from its own system of units is applied.
4. If the unit is composite, each subunit is multiplied or divided per their dimension.
5. The result is passed to {{ntsh}} which applies a normalization formula.
6. The output of {{ntsh}} is added (behaviorally only, i.e. "hidden") into the table as usual, via the data-sort-value attribute of a table.

More example expressions

Number

⟨{{val|  1234567.1234567   }}⟩ → ⟨⟩

Uncertainty

Units

Exponents

Prefix/suffix

Numerator/denominator

Repeating digits

{{val|1.2|end={{overline|34}}|e=7|ul=W|up=m2}} →

Even more examples

See the testcases at {{val/testcases}}.

FAQ and comments

Q. Why should I use Val?

A1. Val formats numbers:

• inserts spaces between groups of digits, meeting MoS standards,
• formats standard uncertainties in measurements, providing a ± character, correct spacing, and correct alignment,
• formats exponents of 10 and scientific notation,
• replaces "-" (hyphen) with a "−" (minus sign).

A2. Val preserves spacing:

• It makes sure the value does not wrap at the end of a line, so that it can always be read as a single value on one line in the text.
• It spaces the various parts of the value where they should be.

A3. Configuring Val gives you your own code for automating the markup for, and a link to, any units in the entire Encyclopedia.

A4. Val helps make Wikipedia more consistent. It adheres to the Wikipedia Manual of Style for numbers. Updates to the MoS can be applied to this template and result in automatic modification on values that use it. All this makes sure all values on all pages have the same look and feel because they will all use the same spacing, font size, positioning, etc, and makes updating and checking by the bots easier because they can recognize a value for what it is.

Q. Why not use <math>?

A. For the same reasons HTML might be preferred over TeX:

• Because the font in math tags differs both in face and size from the prose, which can disturb the layout of a page when used inline with the prose.
• You cannot cut and paste a bitmap image rendered by the LaTeX.
• Images are slower to load and use more bandwidth, which is especially bad for the mobile version of Wikipedia.
• <math> does not automatically easily align to the Manual of Style for numbers.

Q. Are there any known issues with Val?

A1: This template is now a new Lua module as of Aug 6, 2015. Technically, there is no good reason not to try Val.

A2. Issues are solved rapidly by an active set of responsive template coders. See the talk page.

Q. How should I use Val?

A1. Val probably already has your unit on its current list. If not, add your own unit there.

A2. To avoid overlinking, switch from |ul= to |u= and from |upl= to |up=.

A3. Any time you have a unit to link or a table to sort, Val already setup with that unit's link and sorting value.

A3. Use Val along with {{Convert}}. See how to add units to Convert.

A4. Where consistent styling of long list articles, with many hundreds or thousands of numbers or units is needed.

Redirects

• Template:Units

See also

• Module:Val
• Module:Val/units
• Module:Convert/data
• Template:Convert
• Template:Gaps
• Template:Round
• Template:Scinote to display a value in scientific notation
• Template:10^ to display a power of ten

TemplateData

This is the TemplateData for this template used by TemplateWizard, VisualEditor and other tools.

TemplateData for Val

This template is used to easily present values in scientific notation, including uncertainty and/or units, as prescribed by Wikipedia's Manual of Style.

Template parameters

This template prefers inline formatting of parameters.

Parameter		Description	Type	Status
Number	1	A number in decimal point notation or in e notation. The main basis of the Val expression. Example -12.12345e9	String	required
Uncertainty	2	no description	String	optional
Asymmetric uncertainty -	3	no description	String	optional
Format	fmt	By default, numbers are formatted with gaps separating groups of three digits in both integer and fractional part. However, by default, four-digit integers are not formatted; use "gaps" (without quotes) to force gaps. Use the value "commas" (without quotes) to delimit the integer part of the number with commas. Use "none" (without quotes) for no formatting (no gaps or commas). Suggested values gaps commas none Example commas	String	optional
End	end	Put something at the end of the main number (before anything else that might follow).	String	optional
Unit	u	The unit code. A space and the unit will be added after the number. Example m	String	optional
Unit – wikilinked	ul	The unit code that will be wikilinked to a page with information about the unit. A space and this unit will be added after the number. Example m	String	optional
Unit to be prefixed with a slash (/)	up	A unit code, but instead of a space, the template adds a slash and the unit, a "per" unit (the denominator), to form a ratio. Example s	String	optional
Unit to be prefixed with a slash (/) – wikilinked	upl	A wikilinked unit code, but instead of a space, the template adds a slash and the unit, a "per" unit (the denominator), to form a ratio. Example s	String	optional
Prefix	p	Prefix for the entire Val expression. Non-spaced, but accepts markup.	Content	optional
Suffix	s	Suffix for the entire Val expression. Non-spaced, but accepts markup.	Content	optional
Exponent	e	Val alternatively accepts e notation in the first parameter; these are mutually exclusive (see the Number parameter). Example 9	Number	optional
errend	errend	no description	Unknown	optional
4	4	no description	Unknown	optional
5	5	no description	Unknown	optional

The above documentation is transcluded from Template:Val/doc. (edit | history)
Editors can experiment in this template's sandbox (create | mirror) and testcases (create) pages.
Add categories to the /doc subpage. Subpages of this template.