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Swift - lgamma() Function



The Swift lgamma() function returns the natural logarithm of the absolute value of gamma function (log gamma function) of the argument. The log gamma function of x is defined as:

lgamma
Log-gamma Function

Syntax

In Foundation framework, it is defined as follows:

public func lgamma(_ x: CGFloat) -> CGFloat
public func lgamma(_ x: Float) -> Float
public func lgamma(_ x: Float80) -> Float80
public func lgamma(_ __x: Double) -> Double

Parameters

x Specify the value.

Return Value

Returns the natural logarithm of the absolute value of gamma function of the argument.

Example:

The example below shows the usage of lgamma() function.

import Foundation

print("lgamma(-2.5) = \(lgamma(-2.5))")
print("lgamma(-1.5) = \(lgamma(-1.5))")
print("lgamma(0.1) = \(lgamma(0.1))")
print("lgamma(1.5) = \(lgamma(1.5))")
print("lgamma(2.5) = \(lgamma(2.5))")

The output of the above code will be:

lgamma(-2.5) = -0.05624371649767407
lgamma(-1.5) = 0.8600470153764809
lgamma(0.1) = 2.2527126517342055
lgamma(1.5) = -0.12078223763524522
lgamma(2.5) = 0.2846828704729192

❮ Swift Math Functions

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