MATLAB: MATLAB’s accuracy of digits number

accuracydigits

Hi to everyone,

I am dealing with satellite data with accurancy of 25 digits. As I know MATLAB provides computations with maximum 16 digits (long e format). Is there any way to process these data with 25 digits accuracy, because i dont want these values to be rounded?

Thanks a lot

Diamantes

Best Answer

Do you have the Symbolic Math Toolbox? If so, then:

http://www.mathworks.com/help/toolbox/symbolic/vpa.html

Related Solutions

MATLAB: Precision lost when change numbers to string

Similar to how you were doing it:

 ST=join("Hi " + num2str(A',"%1.12e"), newline )
ST = 
    "Hi 2.101000000000e-06
     Hi 2.255670000000e-07
     Hi 1.200041367890e+00
     Hi 6.600005235300e+01"

Or using sprintf like Walter suggested:

 >> sprintf('Hi %1.12e\n',A)
 ans =
    'Hi 2.101000000000e-06
     Hi 2.255670000000e-07
     Hi 1.200041367890e+00
     Hi 6.600005235300e+01
     '

Note that the first method returns a string without a trailing newline and sprintf returns a character vector with one.

MATLAB: How to drop last N round-off error digits

Hi Ilya,

if you are happy with an output, then use fprintf:

a=sqrt(pi);
fprintf('a = %.14g\n', a)
a = 1.7724538509055

Otherwise: use e.g. eps to find the roundoff digit.

a = sqrt(pi);
e = eps(a);
% how many decimal digits it this?
digits = floor(-log10(e));
% cut off the last two
digits = digits - 2;
% round to this digit
aRound = round(a*10^digits) / (10^digits)
aRound =
 1.772453850905500

Titus

Best Answer

Related Solutions

MATLAB: Precision lost when change numbers to string

MATLAB: How to drop last N round-off error digits

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