﻿---
title: Matrix stats aggregation
description: The matrix_stats aggregation is a numeric aggregation that computes the following statistics over a set of document fields: The following example demonstrates...
url: https://www.elastic.co/elastic/docs-builder/docs/2569/reference/aggregations/search-aggregations-matrix-stats-aggregation
products:
  - Elasticsearch
---

# Matrix stats aggregation
The `matrix_stats` aggregation is a numeric aggregation that computes the following statistics over a set of document fields:
<definitions>
  <definition term="count">
    Number of per field samples included in the calculation.
  </definition>
  <definition term="mean">
    The average value for each field.
  </definition>
  <definition term="variance">
    Per field Measurement for how spread out the samples are from the mean.
  </definition>
  <definition term="skewness">
    Per field measurement quantifying the asymmetric distribution around the mean.
  </definition>
  <definition term="kurtosis">
    Per field measurement quantifying the shape of the distribution.
  </definition>
  <definition term="covariance">
    A matrix that quantitatively describes how changes in one field are associated with another.
  </definition>
  <definition term="correlation">
    The covariance matrix scaled to a range of -1 to 1, inclusive. Describes the relationship between field distributions.
  </definition>
</definitions>

<important>
  Unlike other metric aggregations, the `matrix_stats` aggregation does not support scripting.
</important>

The following example demonstrates the use of matrix stats to describe the relationship between income and poverty.

```json

{
  "aggs": {
    "statistics": {
      "matrix_stats": {
        "fields": [ "poverty", "income" ]
      }
    }
  }
}
```

The aggregation type is `matrix_stats` and the `fields` setting defines the set of fields (as an array) for computing the statistics. The above request returns the following response:
```json
{
  ...
  "aggregations": {
    "statistics": {
      "doc_count": 50,
      "fields": [ {
          "name": "income",
          "count": 50,
          "mean": 51985.1,
          "variance": 7.383377037755103E7,
          "skewness": 0.5595114003506483,
          "kurtosis": 2.5692365287787124,
          "covariance": {
            "income": 7.383377037755103E7,
            "poverty": -21093.65836734694
          },
          "correlation": {
            "income": 1.0,
            "poverty": -0.8352655256272504
          }
        }, {
          "name": "poverty",
          "count": 50,
          "mean": 12.732000000000001,
          "variance": 8.637730612244896,
          "skewness": 0.4516049811903419,
          "kurtosis": 2.8615929677997767,
          "covariance": {
            "income": -21093.65836734694,
            "poverty": 8.637730612244896
          },
          "correlation": {
            "income": -0.8352655256272504,
            "poverty": 1.0
          }
        } ]
    }
  }
}
```

The `doc_count` field indicates the number of documents involved in the computation of the statistics.

## Multi Value Fields

The `matrix_stats` aggregation treats each document field as an independent sample. The `mode` parameter controls what array value the aggregation will use for array or multi-valued fields. This parameter can take one of the following:
<definitions>
  <definition term="avg">
    (default) Use the average of all values.
  </definition>
  <definition term="min">
    Pick the lowest value.
  </definition>
  <definition term="max">
    Pick the highest value.
  </definition>
  <definition term="sum">
    Use the sum of all values.
  </definition>
  <definition term="median">
    Use the median of all values.
  </definition>
</definitions>


## Missing Values

The `missing` parameter defines how documents that are missing a value should be treated. By default they will be ignored but it is also possible to treat them as if they had a value. This is done by adding a set of fieldname : value mappings to specify default values per field.

```json

{
  "aggs": {
    "matrixstats": {
      "matrix_stats": {
        "fields": [ "poverty", "income" ],
        "missing": { "income": 50000 }      <1>
      }
    }
  }
}
```