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I'm working with large numbers that I can't have rounded off. Using Lua's standard math library, there seem to be no convenient way to preserve precision past some internal limit. I also see there are several libraries that can be loaded to work with big numbers:
Further, there are many libraries in C that could be called from Lua, if the bindings where established.
Have you had any experience with one or more of these libraries?
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Arbitrary-precision arithmetic, also called big-num arithmetic, multiple precision arithmetic, or sometimes infinite-precision arithmetic, indicates that calculations are performed on numbers whose digits of precision are limited only by the available memory of the host system.
Arbitrary-Precision arithmetic, also known as "bignum" or simply "long arithmetic" is a set of data structures and algorithms which allows to process much greater numbers than can be fit in standard data types.
Some programming languages such as Lisp, Python, Perl, Haskell and Ruby use, or have an option to use, arbitrary-precision numbers for all integer arithmetic. Although this reduces performance, it eliminates the possibility of incorrect results (or exceptions) due to simple overflow.
Representation You might use an array to hold all the digits of large numbers. A more efficient way would be to use an array of 32 bit unsigned integers and store "32 bit chunks" of the large number. You can think of these chunks as individual digits in a number system with 2^32 distinct digits or characters.
Using lbc instead of lmapm would be easier because lbc is self-contained.
local bc = require"bc" s=bc.pow(2,1000):tostring() z=0 for i=1,#s do z=z+s:byte(i)-("0"):byte(1) end print(z) If you love us? You can donate to us via Paypal or buy me a coffee so we can maintain and grow! Thank you!
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