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Use the tan function in APL to compute the tangent of an angle expressed in radians. The tangent is defined as the ratio of the sine to the cosine: tan(x) = sin(x) / cos(x). The function is undefined at odd multiples of π/2, where the cosine is zero. tan is useful when you work with angular data or want to convert a ratio into an angle. In observability contexts, it can be used alongside sin and cos to encode periodic signals or compute angular features for cyclic analysis.

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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.
In Splunk SPL, tan() takes an angle in radians and returns the tangent, just like APL.
| eval tan_val = tan(angle_rad)
In ANSI SQL, TAN() is a standard function with identical behavior.
SELECT TAN(angle_rad) AS tan_val FROM logs

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Usage

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Syntax

tan(x)

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Parameters

NameTypeRequiredDescription
xrealYesThe angle in radians.

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Returns

The tangent of x. The result is unbounded, approaching ±∞ near odd multiples of π/2.

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Example

Use tan to compute the tangent of an angle in radians. Query 
print result = tan(pi() / 4)
Run in Playground Output
result
1.0000
  • sin: Returns the sine. Use sin and cos together for bounded cyclic encoding instead of tan, which is unbounded.
  • cos: Returns the cosine. It is the denominator in tan(x) = sin(x) / cos(x).
  • cot: Returns the cotangent, the reciprocal of tan. Use it when you need the inverse ratio.
  • atan: Returns the arc tangent. Use it as the inverse of tan.
  • isfinite: Returns whether a value is finite. Use it to filter out tan overflow values near π/2 poles.