MATLAB: Raising to the power of large numbers is giving me the wrong answer

digitspowersprecisionpython

If I try 11^16 in matlab, I get: 45949729863572160
If I try 11**16 in python, I get: 45949729863572161
Notice, the last digits are different.
As the numbers get larger, the problem gets worse: 99^95 in Matlab: 3848960788934848|488282452569509484590776195611314554049114673132510910096787679715604422673797115451807631980373077374162416714994207463122539142978709403811688831410945323915071533162168320
99**95 in python: 3848960788934848|611927795802824596789608451156087366034658627953530148126008534258032267383768627487094610968554286692697374726725853195657679460590239636893953692985541958490801973870359499
Notice, where I placed the line, that's they begin to differ
the way I printed the numbers in MatlabŲŒ to control the precision:
num2str(99^95,1000)
the answer I am looking for is the python answer

Best Answer

In general, MATLAB uses double-precision, which roughly means that you can expect 16 digits of precision.
If you need higher precision, then there is a very good user-contributed package for doing that, which you can download from the File Exchange: http://www.mathworks.com/matlabcentral/fileexchange/22725-variable-precision-integer-arithmetic.
v1 = vpi(99);
v2 = vpi(95);
v = v1^v2
v =
    38489607889348486119277958028245967896084511560873660346586279535301
481260085342580322673837686274870946109685542866926973747267258531956576
79460590239636893953692985541958490801973870359499
Related Question