# Categorical visualizations

Categorical visualizations use a categorical attribute and the categories within it to apply styling to discrete categories of the attribute. On raster datasets, it uses a band instead of an attribute.

Categorical visualizations are defined using `"type": "categorical"` and, for every supported style and label property used, either a single value that will apply to all categories or an array of different values for each category.

### Vector example

The Global Power Plants layer in Felt is an example of a categorical layer on a vector dataset

![](https://293097899-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FLlIfNdbm4rCsu755xrdc%2Fuploads%2FngoUiJIM6TONMaazST8X%2FScreenshot%202022-07-28%20at%2017.18.19.png?alt=media\&token=cb9903fd-74c2-48e1-ba82-6b9222251f4f)

and is defined by the following style

```jsx
{
  "version": "2.3",
  "type": "categorical",
  "config": {
    "categoricalAttribute": "primary_fuel",
    "categories": ["Solar", "Hydro", "Wind", "Gas", "Coal", "Oil", "Nuclear"],
    "showOther": false
  },
  "legend": {"displayName": {}},
  "attributes": {
    "capacity_mw": {"displayName": "Capacity (MW)"},
    "name": {"displayName": "Name"},
    "primary_fuel": {"displayName": "Primary Fuel"}
  },
  "paint": {
    "color": [
      "#E5C550",
      "#7AB6C2",
      "#AB71A4",
      "#CC615C",
      "#AD7B68",
      "#EB9360",
      "#DEA145"
    ],
    "isSandwiched": false,
    "opacity": 1,
    "size": [{"linear": [[3, 1.5], [20, 8]]}]
  }
}
```

Notice that we are saying that the `primary_fuel` data attribute will be used to categorize elements and that the possible values of that attribute that we are interested in are `"Nuclear"`, `"Oil"`, `"Coal"`, `"Gas"`, `"Wind"`, `"Hydro"` and `"Solar"`. Also notice that we are defining either a single value that will apply to all categories (i.e. `size`) or a value for each category (i.e. `color`)

### Raster example

The Cropscape CDL layer in Felt is an example of a categorical layer on a raster dataset

![Screenshot 2024-04-12 at 13.25.09.png](https://293097899-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FLlIfNdbm4rCsu755xrdc%2Fuploads%2FhQKcKXrDe4xcNxS0kVAo%2FScreenshot%202024-04-12%20at%2013.25.09.png?alt=media\&token=84c78771-5c4e-4cd5-95eb-09ff2a127755)

and is defined by the following style:

```jsx
{
  "version": "2.3",
  "type": "categorical",
  "config": {
    "categories": [
      254,
      250,
      249,
      248,
      247,
      ...
      4,
      3,
      2,
      1,
      0
    ],
    "showOther": false
  },
  "legend": {
    "displayName": {
      "0": "Background",
      "1": "Corn",
      "2": "Cotton",
      "3": "Rice",
      "4": "Sorghum",
      ...
      "247": "Turnips",
      "248": "Eggplants",
      "249": "Gourds",
      "250": "Cranberries",
      "254": "Dbl Crop Barley/Soybeans"
    }
  },
  "paint": {
    "color": [
      "rgb(38, 113, 0)",
      "rgb(252, 105, 101)",
      "rgb(252, 105, 101)",
      "rgb(252, 105, 101)",
      "rgb(252, 105, 101)",
      ...
      "RGB(255, 158, 15)",
      "RGB(0, 169, 230)",
      "RGB(255, 38, 38)",
      "RGB(255, 212, 0)",
      "rgba(0, 0, 0, 0)"
    ],
    "isSandwiched": false,
    "opacity": 0.93
  }
}
```