Sin¶

Overview¶

The Sin expression computes the trigonometric sine of a numeric value in radians. It extends the UnaryMathExpression class and delegates the actual computation to Java's math.sin function.

Syntax¶

SIN(expr)

sin(col("column_name"))

Arguments¶

Argument	Type	Description
expr	Numeric	The input value in radians for which to compute the sine

Return Type¶

Double - Returns a double-precision floating-point value representing the sine of the input.

Supported Data Types¶

Byte
Short
Integer
Long
Float
Double
Decimal

All numeric input types are implicitly converted to Double for the sine calculation.

Algorithm¶

Takes a single numeric expression as input (child expression)
Evaluates the child expression to get the numeric value
Converts the input value to Double if not already
Delegates to Java's math.sin() function to compute the trigonometric sine
Returns the result as a Double value

Partitioning Behavior¶

This expression preserves partitioning as it operates on individual rows without requiring data movement:

Preserves existing partitioning schemes
Does not require shuffle operations
Can be executed independently on each partition

Edge Cases¶

Null handling: Returns null if the input expression evaluates to null
NaN input: Returns NaN (Not a Number) when input is NaN
Infinite input: Returns NaN for positive or negative infinity inputs
Very large values: May lose precision due to floating-point limitations
Domain: Accepts any finite numeric value (sine function has no domain restrictions)

Code Generation¶

This expression supports Whole-Stage Code Generation (Tungsten) through its parent UnaryMathExpression class, allowing it to generate efficient Java code rather than falling back to interpreted evaluation.

Examples¶

-- Basic sine calculation
SELECT SIN(0);
-- Result: 0.0

-- Sine of π/2 (90 degrees)  
SELECT SIN(1.5707963267948966);
-- Result: 1.0

-- Sine with column reference
SELECT SIN(angle_radians) FROM measurements;

-- Sine of null
SELECT SIN(null);
-- Result: null

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

df.select(sin(col("radians_column")))

// With literal value
df.select(sin(lit(Math.PI / 2)))

// Combined with other functions
df.select(sin(radians(col("degrees_column"))))