# @fiftyone/aggregations ## Hooks ### useAggregation ### @fiftyone/aggregations.useAggregation(options) * **Arguments:** * **options** (`AggregationParams`) * **Return type:** `Array<` `any` `>` A hook for aggregating data from the **FiftyOne** backend. **Aggregation Classes** | JavaScript | Python | |-------------------------------------------------------------|------------------------------------------------------------------------------------------------------------------------------------| | [`Values`](#fiftyone-aggregations.Values) | [`fiftyone.core.aggregations.Values`](../../api/fiftyone.core.aggregations.md#fiftyone.core.aggregations.Values) | | [`Bounds`](#fiftyone-aggregations.Bounds) | [`fiftyone.core.aggregations.Bounds`](../../api/fiftyone.core.aggregations.md#fiftyone.core.aggregations.Bounds) | | [`Count`](#fiftyone-aggregations.Count) | [`fiftyone.core.aggregations.Count`](../../api/fiftyone.core.aggregations.md#fiftyone.core.aggregations.Count) | | [`CountValues`](#fiftyone-aggregations.CountValues) | [`fiftyone.core.aggregations.CountValues`](../../api/fiftyone.core.aggregations.md#fiftyone.core.aggregations.CountValues) | | [`Distinct`](#fiftyone-aggregations.Distinct) | [`fiftyone.core.aggregations.Distinct`](../../api/fiftyone.core.aggregations.md#fiftyone.core.aggregations.Distinct) | | [`HistogramValues`](#fiftyone-aggregations.HistogramValues) | [`fiftyone.core.aggregations.HistogramValues`](../../api/fiftyone.core.aggregations.md#fiftyone.core.aggregations.HistogramValues) | | [`Mean`](#fiftyone-aggregations.Mean) | [`fiftyone.core.aggregations.Mean`](../../api/fiftyone.core.aggregations.md#fiftyone.core.aggregations.Mean) | | [`Std`](#fiftyone-aggregations.Std) | [`fiftyone.core.aggregations.Std`](../../api/fiftyone.core.aggregations.md#fiftyone.core.aggregations.Std) | | [`Sum`](#fiftyone-aggregations.Sum) | [`fiftyone.core.aggregations.Sum`](../../api/fiftyone.core.aggregations.md#fiftyone.core.aggregations.Sum) | | [`Values`](#fiftyone-aggregations.Values) | [`fiftyone.core.aggregations.Values`](../../api/fiftyone.core.aggregations.md#fiftyone.core.aggregations.Values) | **Example** ```typescript const [aggregate, points, loading] = foa.useAggregation({ dataset, filters, view, }); React.useEffect(() => { aggregate( [ new foa.aggregations.Values({ fieldOrExpr: "id", }), new foa.aggregations.Values({ fieldOrExpr: `${path}.point.coordinates`, }), ], dataset.name ); }, [dataset, filters, view, path]); ``` ## Types ### Bounds ### *class* @fiftyone/aggregations.Bounds() ### @fiftyone/aggregations.new Bounds(params) * **Arguments:** * **params** ([`BoundsParams`](#fiftyone-aggregations.BoundsParams)) * **Return type:** `plugins.fiftyone.aggregations.Bounds` ### Count ### *class* @fiftyone/aggregations.Count() ### @fiftyone/aggregations.new Count(params) * **Arguments:** * **params** ([`CountParams`](#fiftyone-aggregations.CountParams)) * **Return type:** `plugins.fiftyone.aggregations.Count` ### CountValues ### *class* @fiftyone/aggregations.CountValues() ### @fiftyone/aggregations.new CountValues(params) * **Arguments:** * **params** ([`CountValuesParams`](#fiftyone-aggregations.CountValuesParams)) * **Return type:** `plugins.fiftyone.aggregations.CountValues` ### Distinct ### *class* @fiftyone/aggregations.Distinct() ### @fiftyone/aggregations.new Distinct(params) * **Arguments:** * **params** ([`DistinctParams`](#fiftyone-aggregations.DistinctParams)) * **Return type:** `plugins.fiftyone.aggregations.Distinct` ### HistogramValues ### *class* @fiftyone/aggregations.HistogramValues() ### @fiftyone/aggregations.new HistogramValues(params) * **Arguments:** * **params** ([`HistogramValuesParams`](#fiftyone-aggregations.HistogramValuesParams)) * **Return type:** `plugins.fiftyone.aggregations.HistogramValues` ### Mean ### *class* @fiftyone/aggregations.Mean() ### @fiftyone/aggregations.new Mean(params) * **Arguments:** * **params** ([`MeanParams`](#fiftyone-aggregations.MeanParams)) * **Return type:** `plugins.fiftyone.aggregations.Mean` ### Std ### *class* @fiftyone/aggregations.Std() ### @fiftyone/aggregations.new Std(params) * **Arguments:** * **params** ([`StdParams`](#fiftyone-aggregations.StdParams)) * **Return type:** `plugins.fiftyone.aggregations.Std` ### Sum ### *class* @fiftyone/aggregations.Sum() ### @fiftyone/aggregations.new Sum(params) * **Arguments:** * **params** ([`SumParams`](#fiftyone-aggregations.SumParams)) * **Return type:** `plugins.fiftyone.aggregations.Sum` ### Values ### *class* @fiftyone/aggregations.Values() ### @fiftyone/aggregations.new Values(params) * **Arguments:** * **params** ([`ValuesParams`](#fiftyone-aggregations.ValuesParams)) * **Return type:** `plugins.fiftyone.aggregations.Values` ### *class* @fiftyone/aggregations.BoundsParams() ### BoundsParams | Name | Type | Description | |--------------------------|--------|---------------| | BoundsParams.expr | `any` | | | BoundsParams.fieldOrExpr | `any` | | | BoundsParams.safe | `any` | | ### *class* @fiftyone/aggregations.CountParams() ### CountParams | Name | Type | Description | |-------------------------|--------|---------------| | CountParams.expr | `any` | | | CountParams.fieldOrExpr | `any` | | | CountParams.safe | `any` | | ### *class* @fiftyone/aggregations.CountValuesParams() ### CountValuesParams | Name | Type | Description | |-------------------------------|--------|---------------| | CountValuesParams.expr | `any` | | | CountValuesParams.fieldOrExpr | `any` | | | CountValuesParams.safe | `any` | | ### *class* @fiftyone/aggregations.DistinctParams() ### DistinctParams | Name | Type | Description | |----------------------------|--------|---------------| | DistinctParams.expr | `any` | | | DistinctParams.fieldOrExpr | `any` | | | DistinctParams.safe | `any` | | ### *class* @fiftyone/aggregations.HistogramValuesParams() ### HistogramValuesParams | Name | Type | Description | |-----------------------------------|--------|---------------| | HistogramValuesParams.auto | `any` | | | HistogramValuesParams.bins | `any` | | | HistogramValuesParams.expr | `any` | | | HistogramValuesParams.fieldOrExpr | `any` | | | HistogramValuesParams.range | `any` | | ### *class* @fiftyone/aggregations.MeanParams() ### MeanParams | Name | Type | Description | |------------------------|--------|---------------| | MeanParams.expr | `any` | | | MeanParams.fieldOrExpr | `any` | | | MeanParams.safe | `any` | | ### *class* @fiftyone/aggregations.StdParams() ### StdParams | Name | Type | Description | |-----------------------|--------|---------------| | StdParams.expr | `any` | | | StdParams.fieldOrExpr | `any` | | | StdParams.safe | `any` | | | StdParams.sample | `any` | | ### *class* @fiftyone/aggregations.SumParams() ### SumParams | Name | Type | Description | |-----------------------|--------|---------------| | SumParams.expr | `any` | | | SumParams.fieldOrExpr | `any` | | | SumParams.safe | `any` | | ### *class* @fiftyone/aggregations.ValuesParams() ### ValuesParams | Name | Type | Description | |---------------------------|--------|---------------| | ValuesParams.expr | `any` | | | ValuesParams.fieldOrExpr | `any` | | | ValuesParams.missingValue | `any` | | | ValuesParams.unwind | `any` | |