ToRadians¶

Overview¶

The ToRadians expression converts angle values from degrees to radians. It is a unary mathematical expression that applies the standard mathematical conversion formula using Scala's math.toRadians function.

Syntax¶

RADIANS(angle_in_degrees)

// DataFrame API
import org.apache.spark.sql.functions.radians
df.select(radians(col("degrees_column")))

Arguments¶

Argument	Type	Description
child	Expression	The angle value in degrees to be converted to radians

Return Type¶

Double - returns the angle converted to radians as a double-precision floating-point number.

Supported Data Types¶

Numeric types (Int, Long, Float, Double)
Any expression that can be cast to a numeric type

Algorithm¶

Takes the input angle value in degrees as a Double
Applies the mathematical conversion formula: radians = degrees × (π / 180)
Uses Scala's built-in math.toRadians function for the conversion
Returns the result as a Double value
Inherits null handling and type coercion from UnaryMathExpression

Partitioning Behavior¶

How this expression affects partitioning:

Preserves partitioning as it operates on individual rows independently
Does not require shuffle operations
Can be applied within existing partitions without data movement

Edge Cases¶

Null input values return null (inherited from UnaryMathExpression)
Handles infinite values according to IEEE 754 standards
Very large degree values may result in loss of precision in floating-point arithmetic
Negative degree values are converted correctly to negative radian values
Zero degrees converts to zero radians

Code Generation¶

This expression supports Tungsten code generation through its parent class UnaryMathExpression, which generates efficient bytecode for mathematical operations rather than falling back to interpreted mode.

Examples¶

-- Convert 180 degrees to radians
SELECT RADIANS(180);
-- Result: 3.141592653589793

-- Convert multiple angle values
SELECT RADIANS(0), RADIANS(90), RADIANS(180), RADIANS(360);
-- Results: 0.0, 1.5707963267948966, 3.141592653589793, 6.283185307179586

-- Use with column data
SELECT angle_degrees, RADIANS(angle_degrees) as angle_radians 
FROM angles_table;

// DataFrame API usage
import org.apache.spark.sql.functions.radians

// Convert a column of degree values
df.select(radians(col("degrees_column")).alias("radians_column"))

// Chain with other mathematical operations
df.select(sin(radians(col("angle_degrees"))).alias("sine_value"))