> For the complete documentation index, see [llms.txt](https://docs.webgeoda.org/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.webgeoda.org/variables/variable-specification.md).

# Variable Specification

The full variable specification reflects all the options available when specifying your variable. Below are all available variable parameters:

* variable `String`: The name a well-adjusted human person might use to describe your variable
* numerator `String`: The numerator for your variable. If you're only using properties from your geospatial data (eg. GeoJSON properties on each feature), you can call the column name directly here. Otherwise, this should refer to the joined data table you'd like to use.
* nProperty `String`: The data column of your numerator to use (eg. 'Total Population')
* nRange `Number`: For time-series data, specify a temporal range for the variable (eg. 1 - daily, 7 - weekly, etc). Cumulative time-series data can be used by calling this `nRange` with `null`
* nIndex `Number`: ...
* denominator `String`: The denominator for your variable. Same conditions apply as `numerator`!
* dProperty `String`: The data column of your numerator to use (eg. 'Land Area')
* dRange `Number`: See `nRange`. If not declared
* dIndex `Number`: ...
* scale `Number`: The scale calculated values will be mutiplied by. For example, if you're using a percentage variable that is normalized from 0-1, you might set a scale of `100`. For many public health metrics, a scale of values per 10,000 or 100,000 may be useful.
* binning `String`: The binning strategy you want for this variable. By default, natural breaks will be used. Read more on available [binning strategies](https://github.com/nofurtherinformation/webgeoda-gitbook/tree/7710e188a74eaf2084b4fb2441eb259996df3fff/variables/variables/binning-types.md)
* numberOfBins `Number`: The number of bins to be generated. Defaults to 5. Built-in color brewer schemes support 3-9 bins.
* colorScale `Object` or `Array`: A built-in color scale of your choice (eg. `colors.colorBrewer.Reds`) or a custom array of RGB values (eg. `[[0,20,40],[20,40,80],[40,80,120]]`). If using a custom scale, you should include the same number of colors as the number of bins. 
* fixedScale `Array`: Pre-define a range of bins by specifying the breakpoints as an array (eg. `[5,10,15]` will produce bins *Less than 5, 5 to 10, 10 to 15, Greater than 15*)