exp ↗

Use the exp() function to calculate the value of Euler's number e raised to the power of a numeric value.

Syntax

exp(<number>)

Parameters

Name Type Required Description
number integer, float Yes The exponent to which e (approximately 2.71828) is raised. Any real number is valid.

Returns

Type: float

Description: The exp() function returns e raised to the power of the input value (e^x). If the input is null, the function returns null.

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 exp() function accepts any real number as input.
  • Null Handling: If the input expression is null, the function returns null.
  • Identity Value: exp(0) always returns 1.0, since e^0 = 1.
  • Inverse Relationship: The exp() function is the inverse of the natural logarithm ln(). That is, exp(ln(x)) = x for x > 0.
  • Overflow: For very large positive input values, the result may overflow to infinity.
  • Underflow: For very large negative input values, the result approaches 0.0.
  • Common Use Cases: This function is typically used within the alter stage for exponential growth/decay modeling, probability calculations, and scientific computations.

Examples

Example 1: Calculate exponential of literal values

Goal: Calculate e raised to specific powers to verify known mathematical results.

XQL code:

dataset = xdr_data
| limit 1
| alter result1 = exp(0), result2 = exp(1), result3 = exp(-1)
| fields result1, result2, result3

Explanation: You use exp() on three different literal values. exp(0) returns 1.0, exp(1) returns approximately 2.71828 (the value of e), and exp(-1) returns approximately 0.36788 (1/e).

Output:

RESULT1 RESULT2 RESULT3
1.0 2.71828 0.36788

Example 2: Calculate exponential from a field value

Goal: Calculate the exponential of values stored in a dataset field.

XQL code:

config timeframe = 1d
| dataset = sample_xql_raw
| alter exp_result = exp(duration_seconds)
| fields event_id, duration_seconds, exp_result
| limit 3

Explanation: This query computes e raised to the power of each value in the duration_seconds field using exp() in the alter stage. No filtering is needed since exp() accepts any real number.

Output:

EVENT_ID DURATION_SECONDS EXP_RESULT
101 0.0 1.0
102 1.0 2.71828
103 2.0 7.38906

Example 3: Verify inverse relationship with ln

Goal: Demonstrate that exp() and ln() are inverse functions by applying both sequentially.

XQL code:

config timeframe = 1d
| dataset = sample_xql_raw
| filter numeric_value > 0
| alter ln_val = ln(numeric_value)
| alter exp_ln_val = exp(ln_val)
| fields event_id, numeric_value, ln_val, exp_ln_val
| limit 3

Explanation: This query first computes the natural logarithm of numeric_value, then applies exp() to the result. The final value exp_ln_val should match the original numeric_value, confirming the inverse relationship exp(ln(x)) = x.

Output:

EVENT_ID NUMERIC_VALUE LN_VAL EXP_LN_VAL
101 5.0 1.60944 5.0
102 10.0 2.30259 10.0
103 100.0 4.60517 100.0