<cat>libraryfunc</cat> <function name="IsNearlyEqual" parent="math" type="libraryfunc"> <description>Checks if two floating point numbers are nearly equal.</description> <realm>Shared and Menu</realm> <added>2025.01.22</added> <file line="275-L281">lua/includes/extensions/math.lua</file> <args> <arg name="a" type="number">The first number to compare.</arg> <arg name="b" type="number">The second number to compare.</arg> <arg name="tolerance" type="number" default="1e-8">The maximum difference between the two numbers to consider them equal.</arg> </args> <rets> <ret name="" type="boolean">True if the difference between the two numbers is less than or equal to the tolerance.</ret> </rets> </function></function>⤶ ⤶ <example>⤶ <description> Shows the problem known as a [floating-point error](https://en.wikipedia.org/wiki/Floating-point_arithmetic#Accuracy_problems), due to the limited precision of decimal numbers in hardware. </description>⤶ <code>⤶ print( 0.1 + 0.2 == 0.3 ) -- Which is mathematically true.⤶ print( string.format( "%.32f", 0.1 + 0.2 ) ) -- Outputs the result with up to 32 decimal numbers.⤶ </code>⤶ <output>⤶ ```⤶ false⤶ 0.30000000000000004440892098500626⤶ ```⤶ </output>⤶ ⤶ </example>⤶ ⤶ <example>⤶ <description> Shows the workaround using `math.IsNearlyEqual()`. </description>⤶ <code>⤶ print( math.IsNearlyEqual( 0.1 + 0.2, 0.3 ) )⤶ print( string.format( "%.32f", 0.1 + 0.2 ) )⤶ </code>⤶ <output>⤶ ```⤶ true⤶ 0.30000000000000004440892098500626⤶ ```⤶ </output>⤶ </example>