invoke operator

Learn how to use the invoke operator to invoke a lambda expression that receives the source of invoke as a tabular parameter argument

Invokes a lambda expression that receives the source of invoke as a tabular argument.

Syntax

T | invoke function([param1, param2])

Parameters

NameTypeRequiredDescription
Tstring✔️The tabular source.
functionstring✔️The name of the lambda let expression or stored function name to be evaluated.
param1, param2 …stringAny additional lambda arguments to pass to the function.

Returns

Returns the result of the evaluated expression.

Example

This example shows how to use the invoke operator to call lambda let expression:

// clipped_average(): calculates percentiles limits, and then makes another 
//                    pass over the data to calculate average with values inside the percentiles
let clipped_average = (T:(x: long), lowPercentile:double, upPercentile:double)
{
   let high = toscalar(T | summarize percentiles(x, upPercentile));
   let low = toscalar(T | summarize percentiles(x, lowPercentile));
   T 
   | where x > low and x < high
   | summarize avg(x) 
};
range x from 1 to 100 step 1
| invoke clipped_average(5, 99)

Output

avg_x
52