Computes an approximation for a specified quartile across all row values in a column or group. Input column can be of Integer or Decimal. |

- If a row contains a missing or null value, it is not factored into the calculation. If the entire column contains no values, the function returns a null value.
- When used in a
`pivot`

transform, the function is computed for each instance of the value specified in the`group`

parameter. See Pivot Transform. The approximate percentile functions utilize a different algorithm for efficiently estimating quantiles for streaming and distributed processing, depending on the running environment where the function is computed.

**Tip:**Approximation functions are suitable for larger datasets. As the number of rows increases, accuracy and calculation performance improves for these functions.- For an exact calculation of this function, see QUARTILE Function.

Quartiles are computed as follows:

Quartile | Description |
---|---|

0 | Minimum value |

1 | 25th percentile |

2 | Median value |

3 | 75th percentile and higher |

approximatequartile(myScores, 3) |

**Output:** Computes the approximate value that is at the 3rd quartile across all values in the myScores column.

approximatequartile(function_col_ref,num_quartile) [group:group_col_ref] [limit:limit_count] |

Argument | Required? | Data Type | Description |
---|---|---|---|

function_col_ref | Y | string | Name of column to which to apply the function |

num_quartile | Y | integer | Integer value (0-3) of the quartile to compute |

dec_error_bound | N | decimal | Error factor for computing approximations. Decimal value represents error factor as a percentage (`0.4` is 0.4%). |

For more information on the `group`

and `limit`

parameters, see Pivot Transform.

Name of the column the values of which you want to calculate the quartile. Column must contain Integer or Decimal values.

- Literal values are not supported as inputs.
- Multiple columns and wildcards are not supported.

Required? | Data Type | Example Value |
---|---|---|

Yes | String (column reference) | ```
precipitationIn
``` |

Integer literal value indicating the quartile that you wish to compute. Input value must be between `0`

and `3`

, inclusive.

- Column or function references are not supported.
- Multiple columns and wildcards are not supported.

Required? | Data Type | Example Value |
---|---|---|

Yes | Integer | `3` |

As needed, you can insert an error boundary factor as a parameter into the computation of this approximate value.

This value must be a Decimal literal value.- This decimal value represents the percentage error factor. By default, this value is
`0.5`

(0.5%).

Required? | Data Type | Example Value |
---|---|---|

No | Decimal (literal) | ```
0.01
``` |