num2str, accuracy, precision, rounding error
조회 수: 28 (최근 30일)
이전 댓글 표시
Please have a look at this code ...
b = 1.00000001;
a = num2str(b,'%.100f')
a = 1.0000000099999999000000000000000000000000000000000000000000000000000000000000000000000000000000000000
a = num2str(b,'%.10f')
a = 1.0000000100
Why is the result different?
How to obtain the right result in the first case?
댓글 수: 0
답변 (1개)
Jyotish Robin
2017년 1월 17일
Hi Lu,
By default, MATLAB stores all numeric values as double-precision floating point. The fact is, almost all decimal numbers are NOT representable exactly in floating point arithmetic as a double. This is why this issue is completely about precision and the binary form that a double comprises.
You can read in detail about this here: http://stackoverflow.com/questions/10904132/conversion-of-numeric-to-string-in-matlab
If you are interested in converting a double or single input to the exact decimal string, you could refer the following file exchange submission: https://www.mathworks.com/matlabcentral/fileexchange/22239-num2strexact--exact-version-of-num2str-
Hope the above suggestions help!
댓글 수: 0
참고 항목
카테고리
Help Center 및 File Exchange에서 Characters and Strings에 대해 자세히 알아보기
제품
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!