series_fill_backward()
Applies to: ✅ Microsoft Fabric ✅ Azure Data Explorer ✅ Azure Monitor ✅ Microsoft Sentinel
Performs a backward fill interpolation of missing values in a series.
An expression containing dynamic numerical array is the input. The function replaces all instances of missing_value_placeholder with the nearest value from its right side (other than missing_value_placeholder), and returns the resulting array. The rightmost instances of missing_value_placeholder are preserved.
Syntax
series_fill_backward(
series[,
missing_value_placeholder])
Learn more about syntax conventions.
Parameters
Name | Type | Required | Description |
---|---|---|---|
series | dynamic |
✔️ | An array of numeric values. |
missing_value_placeholder | scalar | Specifies a placeholder for missing values. The default value is double( null) . The value can be of any type that will be converted to actual element types. double (null), long (null) and int (null) have the same meaning. |
Note
- If you create series using the make-series operator, specify null as the default value to use interpolation functions like
series_fill_backward()
afterwards. See explanation. - If missing_value_placeholder is
double
(null), or omitted, then a result may contain null values. To fill these null values, use other interpolation functions. Only series_outliers() supports null values in input arrays. series_fill_backward()
preserves the original type of the array elements.
Returns
series with all instances of missing_value_placeholder filled backwards.
Example
let data = datatable(arr: dynamic)
[
dynamic([111, null, 36, 41, null, null, 16, 61, 33, null, null])
];
data
| project
arr,
fill_backward = series_fill_backward(arr)
Output
arr |
fill_backward |
---|---|
[111,null,36,41,null,null,16,61,33,null,null] | [111,36,36,41,16,16,16,61,33,null,null] |
Tip
Use series_fill_forward or series-fill-const to complete interpolation of the above array.