Skip to main content
Use the exp2 function in APL to compute the base-2 exponential of a value: 2^x. It’s the inverse of the base-2 logarithm function log2. exp2 is useful when you work with data measured on a binary scale, such as memory sizes, network bandwidths, or binary tree depths. You can also use it to reverse a log2 transformation and recover values on the original scale.

​
For users of other query languages

If you come from other query languages, this section explains how to adjust your existing queries to achieve the same results in APL.
Splunk SPL doesn’t include a built-in exp2() function. You compute it as pow(2, x).
| eval result = pow(2, x)
Standard SQL does not define EXP2(). You compute it using POWER(2, x).
SELECT POWER(2, x) AS result FROM logs

​
Usage

​
Syntax

exp2(x)

​
Parameters

NameTypeRequiredDescription
xrealYesThe exponent value.

​
Returns

The base-2 exponential of x: 2^x.

​
Example

Use exp2 to recover the geometric mean of request durations from a log2-transformed average. Query 
['sample-http-logs']
| where req_duration_ms > 0
| summarize geometric_mean = exp2(avg(log2(req_duration_ms))) by bin(_time, 1h)
| project _time, geometric_mean
Run in Playground Output
_timegeometric_mean
2024-11-14 10:00:0085.3
2024-11-14 11:00:0092.7
2024-11-14 12:00:0078.1
  • log2: Returns the base-2 logarithm. Use it as the inverse of exp2.
  • exp: Returns e^x. Use it for natural-log-scale transformations instead of base-2.
  • exp10: Returns 10^x. Use it for base-10 (order-of-magnitude) scales.
  • pow: Raises any base to a power. Use it when neither e, 2, nor 10 is the intended base.
  • log: Returns the natural logarithm. Use it together with exp for natural-log-scale analysis.