This is adocumentationsubpage forTemplate:Val. It may contain usage information,categories and other content that is not part of the original template page.

This template is used onapproximately 43,000 pages and changes may be widely noticed. Test changes in the template's/sandbox or/testcases subpages, or in your ownuser subpage. Consider discussing changes on thetalk page before implementing them.

This templateshould not be used incitation templates such asCitation Style 1 andCitation Style 2, because it includes markup that will pollute theCOinS metadata they produce; seeWikipedia:COinS.

This template usesLua: Module:Val (sandbox) Module:Val/units (sandbox)

This template is used to easily present values inscientific notation, including uncertainty and/or units, as prescribed by Wikipedia'sManual of Style atMOS:NUM.

Val specializes in numericvalues, especially those withscientific notations,uncertainty notations, and those with measurementvalues 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:123456.78901, or with|fmt=commas →123,456.78901
• {{val|number|number}} →value ±uncertainty, like123,478±56
• {{val|number|(number)}} →value(uncertainty), like12,345(56)
• {{val|number|number|number}} →value^+uncertainty
  _{−uncertainty} like1234+56
  −78

Express a measurement value:{{val|4|ul=m2}} →4 m². Them2 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". SeeModule:Val/units.

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

• {{val|number|ul=unit code}} →numbersymbol, such as9.8 km²
• {{val|number|u=unit code}} →number symbol, such as9.8 km²
• {{val|number|u=unit code|upl=unit code}} →number symbol/symbol, such as9.8 gal/min
• {{val|number|ul=unit code|up=unit code}} →number symbol/symbol, such as9.8 pc/year

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

• {{val|5.4|u=[[kg]]&sdot;[[meter|m]]/s<sup>2</sup>}} →5.4 kg⋅m/s²
• {{val|7.6|u=[[metre per second squared|m/s<sup>2</sup>]]}} →7.6 m/s²

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

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

• {{val|7600|u=C&sdot;Ga|p=>|s=<}} →>7600 C⋅Ga<
• {{val|7600|u=C|p=<span style="color:green"><sup>|s=</sup></span>}} →^7600 C

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

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 togrammatically join the first and third numbers.

Val clears surrounding spaces in its unnamed parameters.

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 onCategory:Pages with incorrect formatting templates use.

Val checks for unsupported parameters and gives a relatively subtle warning if found. Seetracking 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}} →1.23 m/sError in {{val}}: Val parameter "exp=6" is not supported
• {{val|1.23|us=kbit/s}} →1.23Error in {{val}}: Val parameter "us=kbit/s" is not supported
• {{val|1.23|.05|.04|.03|u=m/s}} →1.23+0.05
  −0.04 m/sError in {{val}}: Val parameter 4 ignored

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

TheMOS 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= (seeabove).

The sort key for each sortable unit is visible atTemplate: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}}|}|}

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 ownsystem of units is applied.
4. If the unit is composite, each subunit is multiplied or divided per theirdimension.
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.

{{val|1234567.1234567}} →1234567.1234567
⟨{{val|  1234567.1234567   }}⟩ → ⟨1234567.1234567⟩
{{val|.1234567|fmt=commas}} →0.1234567
{{val|+1234567|fmt=commas}} →+1,234,567
{{val|-1234567}} →−1234567

{{val|1.234|0.005}} →1.234±0.005
{{val|1.234|0.005|e=3}} →(1.234±0.005)×10³
{{val|1.234|+0.005|-0.006}} →1.234+0.005
−0.006
{{val|1.234|(5)}} →1.234(5)

{{val|1.234|u=m}} →1.234 m
{{val|1.234|u=m2}} →1.234 m²
{{val|1.234|ul=m}} →1.234 m
{{val|123.4|ul=USgal}} →123.4 US gal
{{val|12.34|ul=mpgimp}} →12.34 mpg_‑imp

{{val|12.34|u=deg}} →12.34°
{{val|1.234|0.005|u='}} →1.234′±0.005′
{{val|1.234|+0.005|-0.006|u="}} →1.234″+0.005″
−0.006″

{{val|1.234|u=%}} →1.234%
{{val|1.234|end= [[m/s]]}} →1.234 m/s

{{val|12.34|u=degC}} →12.34 °C
{{val|12.34|u=K}} →12.34 K

{{val|e=5}} →10⁵
{{val|e=5|ul=m}} →10⁵ m

{{val|1.234e5|ul=m}} →1.234×10⁵ m
{{val|1.234|e=5|ul=m}} →1.234×10⁵ m

{{val|1.234e7|0.056}} →(1.234±0.056)×10⁷
{{val|1.234|0.056|e=7}} →(1.234±0.056)×10⁷

{{val|1.23456e-9|+0.00007|-0.00008|ul=m/s}} →1.23456+0.00007
−0.00008×10⁻⁹ m/s
{{val|1.23456|+0.00007|-0.00008|e=-9|ul=m/s}} →1.23456+0.00007
−0.00008×10⁻⁹ m/s

{{val|1.234e7|0.056|ul=psi}} →(1.234±0.056)×10⁷ psi
{{val|1.234|0.056|e=7|ul=psi}} →(1.234±0.056)×10⁷ psi

{{val|1.234e-2|(5)}} →1.234(5)×10⁻²
{{val|1.234|(5)|e=-2}} →1.234(5)×10⁻²

{{val|12.34|p=Δ }} →Δ 12.34
{{val|12.34|u=%|p=≅}} →≅12.34%
{{val|12.34|0.25|s=%}} →12.34±0.25%

{{val|1.234|e=7|ul=W|up=m2}} →1.234×10⁷ W/m²

{{val|1.2|end={{overline|34}}|e=7|ul=W|up=m2}} →1.234×10⁷ W/m²

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

Q. Why should I use Val?

A1. Val formats numbers:

• inserts spaces between groups of digits, meetingMoS standards,
• formats standarduncertainties in measurements, providing a ± character, correct spacing, and correct alignment,
• formatsexponents of 10 andscientific notation,
• replaces "-" (hyphen) with a "−" (minus sign).

A2. Val preserves spacing:

• It makes sure the value does notwrap 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 theWikipedia 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 samelook and feel because they will all use the samespacing,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 reasonsHTML might be preferred over TeX:

• Because thefont 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 cannotcut 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 onits current list. If not, add your own unit there.

A2. To avoidoverlinking, 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}}. Seehow to add units to Convert.

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

• Template:Units

• 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

• Template documentation pages