Is it posible to change the number of digits Matlab works with?

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Gianni 2021-9-25

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回答： Walter Roberson 2021-9-26

I´m using the QuTip toolbox to generate random density matrices. These have the strandard 16 digits. However, i would like them to only have 5 so i can export them easly, without having to round them, losing imformation. Maybe there's a better way of doing what i need.

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Answer 1

Walter Roberson 2021-9-26

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You would have to use the Fixed Point Toolbox. This might require some modifications to QuTip toolbox; Fixed Point Designer would help with that.

You could also consider taking the generated matrices and

M = floor(M * 1e5)/1e5;

Reminder, though: Double precision floating point numbers cannot exactly represent 1e-5 so a number such as 0.34567 is going to be rounded by MATLAB, because internally it is represented as a value equal to 0.345669999999999977280396024070796556770801544189453125