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NOTE:  Trifacta Wrangler is a free product with limitations on its features. Some features in the documentation do not apply to this product edition. See Product Limitations.

   

For input values between -1 and 1 inclusive, this function returns the angle in radians whose tangent value is the input. This function is the inverse of the tangent function. The value can be a Decimal or Integer literal or a reference to a column containing numeric values.

NOTE: While this function returns values outside of the range -1 <= x <= 1, those values are not considered valid.

For more information on the tangent function, see TAN Function.

arc cotangent:

Input rangeOutput computation
x>0atan(1/x)
x<=0

atan(1/x) + PI()

Wrangle vs. SQL: This function is part of Wrangle , a proprietary data transformation language. Wrangle is not SQL. For more information, see Wrangle Language.

Basic Usage

Numeric literal example:

atan(0.5)

Output: Returns the computation of the arc tangent of 0.5. Output value is in radians. 

Column reference example:

atan(X)

Output: Returns the arc tangent of the values in X column.

Syntax and Arguments

atan(numeric_value)


ArgumentRequired?Data TypeDescription
numeric_valueYstring, decimal, or integerName of column, Decimal or Integer literal, or function returning those types to apply to the function

For more information on syntax standards, see Language Documentation Syntax Notes.

numeric_value

Name of the column, Integer or Decimal literal, or function returning that data type to apply to the function.

  • Missing input values generate missing results.
  • Literal numeric values should not be quoted. Quoted values are treated as strings.
  • Multiple columns and wildcards are not supported.

Usage Notes:

Required?Data TypeExample Value
YesString (column reference) or Integer or Decimal literal0.5

Examples

Tip: For additional examples, see Common Tasks.

Example - Trigonometry Arc functions

This example illustrates how to apply the inverse trigonometric (Arc) functions to your transformations. 

Functions:

ItemDescription
ASIN Function For input values between -1 and 1 inclusive, this function returns the angle in radians whose sine value is the input. This function is the inverse of the sine function. The value can be a Decimal or Integer literal or a reference to a column containing numeric values.
ACOS Function For input values between -1 and 1 inclusive, this function returns the angle in radians whose cosine value is the input. This function is the inverse of the cosine function. The value can be a Decimal or Integer literal or a reference to a column containing numeric values.
ATAN Function For input values between -1 and 1 inclusive, this function returns the angle in radians whose tangent value is the input. This function is the inverse of the tangent function. The value can be a Decimal or Integer literal or a reference to a column containing numeric values.

Also:

ItemDescription
ROUND Function Rounds input value to the nearest integer. Input can be an Integer, a Decimal, a column reference, or an expression. Optional second argument can be used to specify the number of digits to which to round.
DEGREES Function Computes the degrees of an input value measuring the radians of an angle. The value can be a Decimal or Integer literal or a reference to a column containing numeric values.

NOTE: These functions are valid over specific ranges.

The following functions are computed using the above functions.

  • Arccotangent. Computed using ATAN function. See below.
  • Arcsecant. Computed using ACOS function. See below.
  • Arccosecant. Computed using ASIN function. See below.

Source:

In the following sample, input values are in radians. In this example, all values are rounded to two decimals for clarity.


Y
-1.00
-0.75
-0.50
0.00
0.50
0.75
1.00

Transformation:

Arcsine:

Valid over the range (-1 <= Y <= 1)

Transformation Name New formula
Parameter: Formula type Single row formula
Parameter: Formula round(degrees(asin(Y)), 2)
Parameter: New column name 'asinY'

Arccosine: 

Valid over the range (-1 <= Y <= 1)

Transformation Name New formula
Parameter: Formula type Single row formula
Parameter: Formula round(degrees(acos(Y)), 2)
Parameter: New column name 'acosY'

Arctangent: 

Valid over the range (-1 <= Y <= 1)

Transformation Name New formula
Parameter: Formula type Single row formula
Parameter: Formula round(degrees(atan(Y)), 2)
Parameter: New column name 'atanY'

Arccosecant:

This function is valid over a set of ranged inputs, so you can use a conditional column for the computation. 

Transformation Name Conditional column
Parameter: Condition type if...then...else
Parameter: If (Y <= -1) || (Y >= 1)
Parameter: Then round(degrees(asin(divide(1, Y))), 2)
Parameter: New column name 'acscY'

Arcsecant:

Same set of ranged inputs apply to this function. 

Transformation Name Conditional column
Parameter: Condition type if...then...else
Parameter: If (Y <= -1) || (Y >= 1)
Parameter: Then round(degrees(acos(divide(1, Y))), 2)
Parameter: New column name 'asecY'

Arccotangent:

For this function, the two different ranges of inputs have different computations, so an else condition is added to the transformation. 

Transformation Name Conditional column
Parameter: Condition type if...then...else
Parameter: If Y > 0
Parameter: Then round(degrees(atan(divide(1, Y))), 2)
Parameter: Else round(degrees(atan(divide(1, Y)) + pi()), 2)
Parameter: New column name 'acotY'

Results:

YacotYasecYacscYatanYacosYasinY
-1.00-41.86180.00-90.00-45.00180.00-90.00
-0.75-49.99nullnull-37.00139.00-49.00
-0.50-60.29nullnull-27.00120.00-30.00
0.00nullnullnull0.0090.000.00
0.5063.44nullnull27.0060.0030.00
0.7553.13nullnull37.0041.0049.00
1.0045.000.0090.0045.000.0090.00

See Also for EXAMPLE - Trigonometry Arc Functions:

See Also for ATAN Function:

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