Template:Calculator
This template is for creating interactive calculators. It requires the calculator gadget. You must not have opted out of the calculator gadget for this to work.
You can use this template multiple times on a page to make input widgets, with some of the widgets having formulas based on other widgets, like a spreadsheet.
You can use {{Calculator label}} to mark text as a label for a calculator widget.
Example[edit]
{{calculator|id=a|default=2|size=4}} × {{calculator|id=b|default=2|size=4}} = {{calculator|id=c|formula=a*b|default=4|size=8|readonly=true|type=text}}
produces:
2 × 2 = 4
BMI calculator metric[edit]
{| class="wikitable" style = "float: left; margin-left:15px;"
|+ Metric
|-
| {{calculator label|Weight|for=weightkg}} || {{calculator|id=weightkg|size=3}} kg
|-
| {{calculator label|Height|for=heightcm}} || {{calculator|id=heightcm|size=3}} cm
|-
| BMI || '''{{calculator|id=bmimetric|type=plain|formula=round(weightkg/pow(heightcm/100,2))|style=min-width:3ch;display:inline-block}} kg/m<sup>2</sup>'''
|}
| Weight | kg |
| Height | cm |
| BMI | kg/m2 |
BMI calculator imperial[edit]
You can put widgets inside tables:
<table class="wikitable">
<tr><td>Imperial</td></tr>
<tr><td>Weight</td><td>{{calculator|id=weight|size=3}} lbs</td></tr>
<tr><td>Height</td><td>{{calculator|id=heightFeet|size=1}} feet {{calculator|id=heightInches|size=2}} inches</td></tr>
<tr><td>BMI</td><td>'''{{calculator|id=bmi|type=plain|formula=round(100*weight*703/pow(heightFeet*12+heightInches,2))/100}} kg/m<sup>2</sup>'''</td></tr>
</table>
| Imperial | |
| Weight | lbs |
| Height | feet inches |
| BMI | kg/m2 |
Formula[edit]
Formulas use normal math syntax, with english words representing other input boxes. e.g. sin(1+foo*2) would multiply the foo box by 2, add 1 and take the sine of the whole thing. All calculations are done using IEEE 754 double precision floating point numbers.
Operators supported include: +, -, *, ×, /, ÷, % (percent is the modulo operator). Exponentiation must use the pow() function.
Math functions supported include: 'abs', 'acos', 'acosh', 'asin', 'asinh', 'atan', 'atan2', 'atanh', 'ceil', 'cos', 'cosh', 'exp', 'floor', 'hypot', 'log', 'log10', 'log2', 'max', 'min', 'pow', 'random', 'sign', 'sin', 'sinh', 'sqrt', 'tan', 'tanh', 'trunc'
These have the same definition as in javascript. In particular, that means that log() is log base-e. The exception is round, which we use our own definition of
The following additional functions are supported which are not from javascript Math library:
- ifzero - if first argument is epsilon away from zero, return second argument, otherwise third argument
- ifnan - if first argument is not a number (NaN), return second argument, otherwise third argument
- iffinite - if the first argument is finite return second argument, otherwise return third argument.
- coalesce - return the first argument that is not NaN.
- ifpositive - if first argument is ≥ 0 return second, otherwise return third. (Note this tries to account for floating point error)
- ifequal - If first and second argument are the same, accounting for floating point error.
- round - A round function. Unlike javascript round(), this implements round half away from zero ("commercial rounding"). It takes an optional second argument to say how many decimal digits to rount to. e.g. round( 3.125, 2 ) = 3.13, round( -3.125, 2 ) = -3.13.
- jsround - Use javascript round. This does round half towards positive infinity with a precision of 0. See mdn docs
Numbers can be integers, decimals or scientific notation. For example: 1, 2.84543, 3.12E6, -5, 3.45×10⁻⁴⁵
The following constants are supported: Infinity, -Infinity, NaN, pi, π, EPSILON
At the moment, relational operators like ≤ or ≠ and IF statements are not supported. This might be added in a future version if needed. This can be worked around by using ifzero and ifpositive functions.
Fallback[edit]
Users who do not have the gadget enabled or have JS disabled, will not see the input boxes. Instead they will just see the default value for each box. With a good choice of default, this can be sufficient.
For example, if you have ''sin({{calculator|id=sine|type=text|default=0.5|size=4}}π)={{calculator|type=plain|default=1.00|decimals=2|formula=sin(sine*π)|id=sineres}}'' to make sin(0.5π)=1.00, the non-js user will lose the interactivity, but they will still see the equation.
If you want more sophisticated fallbacks, you can use the calculatorgadget-enabled and calculatorgadget-fallback CSS classes.
<div class="calculatorgadget-enabled" style="display:none">This text is only shown if the gadget is enabled. {{calculator|type=text|size=20|default=100|id=xyz}} </div>
<div class="calculatorgadget-fallback">This text is only shown if the gadget is disabled</div>
Which produces:
Template arguments[edit]
Note: Not all arguments work on all input types.
- id
- The id for this field, used in formulas of other fields (Has to be english characters)
- default
- The starting value
- readonly
- Make field read only
- formula
- The formula to calculate this field. See below for what is supported
- type
- Type of field. Currently supported are plain, number, text, radio and checkbox. Checkbox and radio can be useful in combination with TemplateStyles.
- size
- how big to make the input box (In terms of number of letters that can fit in the box)
- max
- Max number allowed (number type only)
- min
- Min number allowed (number type only)
- placeholder
- Placeholder text that shows up light grey when there is no input
- step
- How big the interval is for type=number inputs
- style
- Custom CSS to use for the element.
- name
- When using type=radio, the name of the radio group.
- precision
- Format field to this many significant digits. (Only works type=plain and type=text)
- exponential-precision
- Format field to this many significant digits in scientific notation. (Only works type=plain and type=text)
- decimals
- Format field to this many decimal digits. (Only works type=plain and type=text)
- NaN-text
- Use this text instead of NaN when result is not a number (Only works type=plain and type=text)
Add a calculator widget to the page. Like a spreadsheet you can refer to other widgets in the same page.
| Parameter | Description | Type | Status | |
|---|---|---|---|---|
| id | id | The id for this input. This is used to reference it in formula of other calculator templates | String | required |
| type | type | What type of input box
| String | required |
| formula | formula | Formula to calculate this field
| String | suggested |
| readonly | readonly | Make input box readonly to user input | Boolean | optional |
| size | size | Size of input box (How many characters it will fit) | Number | optional |
| max | max | max number allowed (type=number inputs only) | Number | optional |
| min | min | min number allowed (type=number inputs only) | Number | optional |
| placeholder | placeholder | Text to put as a placeholder in empty input | String | optional |
| step | step | How much to increment a type=number input box
| Number | optional |
| default | default | Default value for this field | String | suggested |
| style | style | CSS to style the input element with | String | optional |
| name | name | For type=radio what group to assign the radio button to | Unknown | optional |
| precision | precision | Format to this many significant digits, using decimal notation except for really large numbers [Only applies to type=number or type=plain]
| Number | optional |
| exponential-precision | exponential-precision | Format to this many significant digits, using scientific notation [Only applies to type=number or type=plain]
| Number | optional |
| decimals | decimals | Format to a fixed number of decimal digits [Only applies to type=number or type=plain]
| Number | optional |
| NaN-text | NaN-text | Use this text instead of NaN to signify "not a number". Only applies to format=plain or format=text. Plaintext only; wikitext is not supported
| String | optional |