Calculates the arc tangent of a value; the returned angle is in the range -π/2 through π/2.

Note

Math functions on ARM architecture may return different results in very high-precision calculationsc compared to Intel/AMD architectures.

ParameterTypeRequiredDefault ValueDescription
asstringoptional[a] _arctan The name of the output field.
field[b]stringrequired   The name of the input field.

[a] Optional parameters use their default value unless explicitly set.

[b] The parameter name field can be omitted.

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math:arctan() Examples

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Calculate Arc Tangent of Value

Calculate the arc tangent using the math:arctan() function

Query
logscale
x := 1.0
        | math:arctan(x, as=angle)
Introduction

In this example, the math:arctan() function is used to calculate the arc tangent of 1.0, which represents a slope of 1 (45-degree angle).

Step-by-Step

  1. Starting with the source repository events.

  2. logscale
    x := 1.0

    Assigns the value 1.0 to field x. This value represents a slope of 1 (rise over run), which should result in an angle of π/4 radians (45 degrees).

  3. logscale
    | math:arctan(x, as=angle)

    Calculates the arc tangent of the value in field x and returns the result in radians in a field named angle. If the as parameter is not specified, the result is returned in a field named _arctan as default.

  4. Event Result set.

Summary and Results

The query is used to calculate angles from slope values, which is useful in various mathematical and geometric calculations where you need to find an angle from a ratio.

This query is useful, for example, to calculate angles from slopes, determine inclination from gradients, or analyze ratios in trigonometric calculations.

Sample output from the incoming example data:

angle
0.7853981633974483

The result shows that the arc tangent of 1.0 is approximately 0.7854 radians (π/4 radians or 45 degrees). This means a slope of 1 corresponds to a 45-degree angle.

Note that the math:arctan() function only returns values between -π/2 and π/2 radians (-90 to 90 degrees). For full angle determination in all directions (0 to 360 degrees), use math:arctan2() instead.

The math:arctan() function is often used with math:rad2deg() when angles need to be displayed in degrees. For applications requiring angles in all directions, consider using math:arctan2() instead.