MATLAB: The precision digit problem of vpa function

vpa

I got problems that vpa always ouput four decimal digits, and I would like to know how to solve this problem.

You have somehow changed your symbolic preferences. Run

sympref("default")

in the command window to change them to default.

Thanks for your replies. Sorry, maybe I was not precise enough in my question.

I am dealing with numbers like -0.897214128288675 * (1.0e+03).

For my calculation I need more accuracy than above -> 18 digits after the comma would be excellent.

Also, I am working with arrays...

Here you go:

clear all

digits(100);

N=vpa(sym('sqrt(2)'));

sumA = 0;

for i = 1:100

    sumA = sumA + (floor(N*(10^(i-1))) - 10*floor(N*10^(i-2)));

end

disp(sumA)