sqrt ↗

Use the sqrt() function to calculate the square root of a numeric value.

Syntax

sqrt(<number>)

Parameters

Name Type Required Description
number integer, float Yes The numeric value for which to calculate the square root. The value must be greater than or equal to 0.

Returns

Type: float

Description: The sqrt() function returns the non-negative square root of the input value. If the input is null or negative, the function returns null or NaN.

Usage notes

  • Input type: XQL doesn't support NaN or infinite values as input and these value types also can not be returned.
  • Valid Input Range: The input number must be greater than or equal to 0. The square root of a negative number is not a real number.
  • Negative Input: If the input is negative, the function returns NaN or null.
  • Null Handling: If the input expression is null, the function returns null.
  • Identity Values: sqrt(0) returns 0.0, sqrt(1) returns 1.0.
  • Perfect Squares: For perfect squares (for example, 4, 9, 16, 25), the result is an exact integer value represented as a float.
  • Relationship to power(): sqrt(x) is equivalent to power(x, 0.5).
  • Common Use Cases: This function is typically used within the alter stage for distance calculations, standard deviation computations, normalization, and geometric formulas.

Examples

Example 1: Calculate square root of literal values

Goal: Calculate the square root for specific numeric literals to verify known mathematical results.

XQL code:

dataset = xdr_data
| limit 1
| alter result1 = sqrt(4), result2 = sqrt(9), result3 = sqrt(2)
| fields result1, result2, result3

Explanation: sqrt(4) returns 2.0, sqrt(9) returns 3.0, and sqrt(2) returns approximately 1.41421.

Output:

RESULT1 RESULT2 RESULT3
2.0 3.0 1.41421

Example 2: Calculate square root from a field value

Goal: Calculate the square root of values stored in a dataset field, filtering out negative values.

XQL code:

config timeframe = 1d
| dataset = sample_xql_raw
| filter numeric_value >= 0
| alter sqrt_result = sqrt(numeric_value)
| fields event_id, numeric_value, sqrt_result
| limit 3

Explanation: This query first filters the dataset to ensure numeric_value contains only non-negative values, then computes the square root for each value using sqrt() in the alter stage.

Output:

EVENT_ID NUMERIC_VALUE SQRT_RESULT
101 4.0 2.0
102 100.0 10.0
103 25.0 5.0

Example 3: Calculate Euclidean distance using sqrt

Goal: Manually calculate the Euclidean distance between two 2D points using sqrt() and arithmetic functions.

XQL code:

config timeframe = 1d
| dataset = sample_xql_raw
| alter dx = subtract(numeric_value, 10)
| alter dy = subtract(duration_seconds, 5)
| alter distance = sqrt(add(multiply(dx, dx), multiply(dy, dy)))
| fields event_id, numeric_value, duration_seconds, distance
| limit 3

Explanation: This query calculates the Euclidean distance from each point (numeric_value, duration_seconds) to the reference point (10, 5) using the formula sqrt((x2-x1)� + (y2-y1)�).

Output:

EVENT_ID NUMERIC_VALUE DURATION_SECONDS DISTANCE
101 4.0 1.5 7.28011
102 13.0 5.0 3.0
103 10.0 10.2 5.2