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Use the sin function in APL to compute the sine of an angle expressed in radians. The function accepts any real number and returns a value in the range [-1, 1]. sin is most commonly used in observability to encode time-of-day or other periodic signals as cyclic coordinates. When combined with cos, it produces a two-dimensional representation of periodic phenomena that preserves circular distance. For example, you can encode hour-of-day cyclically so that hour 23 and hour 0 are treated as adjacent.

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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, sin() takes an angle in radians and returns the sine, just like APL.
| eval sin_val = sin(angle_rad)
In ANSI SQL, SIN() is a standard function with identical semantics.
SELECT SIN(angle_rad) AS sin_val FROM logs

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Usage

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Syntax

sin(x)

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Parameters

NameTypeRequiredDescription
xrealYesThe angle in radians.

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Returns

The sine of x, a real number in the range [-1, 1].

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Example

Use sin to compute the sine of an angle in radians. Query 
print result = sin(pi() / 2)
Run in Playground Output
result
1
  • cos: Returns the cosine. Use sin and cos together to produce a two-dimensional cyclic encoding of angles.
  • tan: Returns the tangent. Use it when you need the ratio of sine to cosine.
  • asin: Returns the arc sine. Use it as the inverse of sin.
  • pi: Returns the constant π. Use it to construct radian values before calling sin.
  • radians: Converts degrees to radians. Use it to prepare degree inputs before calling sin.