Why are all the negative values in the matrix show as 0?
조회 수: 5 (최근 30일)
이전 댓글 표시
The code below creates a matrix to do calculations, however, the negative values results are show in the matrix as 0. Why would this happen and how to keep those negative values instead of 0. Thank you.
load Foveal
T = ans;
T_1002 = T(matches(T.message,'1002'),:);
T_ENDSACC = T(matches(T.message,'ENDSACC'),:);
[x1 ~] = size(T_ENDSACC);
[x2 ~] = size(T_1002);
T_diff = zeros(x1,x2);
for q = 1:x1
T_diff(q,:) = T_ENDSACC.reltime(q) - T_1002.reltime(:);
end
댓글 수: 0
채택된 답변
Voss
2023년 2월 8일
reltime is of class uint32, as shown here:
load Foveal
T = ans;
class(T.reltime)
An unsigned integer cannot be negative. If you want to allow negative values use a different type such as a signed integer or a floating-point (such as single or double). Here I'll make reltime into a double:
T.reltime = double(T.reltime);
And then run the rest of the code:
T_1002 = T(matches(T.message,'1002'),:);
T_ENDSACC = T(matches(T.message,'ENDSACC'),:);
[x1 ~] = size(T_ENDSACC);
[x2 ~] = size(T_1002);
T_diff = zeros(x1,x2);
for q = 1:x1
T_diff(q,:) = T_ENDSACC.reltime(q) - T_1002.reltime(:);
end
T_diff
댓글 수: 3
Steven Lord
2023년 2월 8일
FYI for the integer types you can use intmin and intmax to determine the range of allowed values for that type.
intmin('uint32')
intmax('uint32')
Assignment of values outside that range truncates.
x = ones(1, 2, 'uint32')
x(1) = -1 % -1 is < intmin('uint32') so MATLAB stores intmin('uint32')
x(2) = 1e11 % 1e11 is > intmax('uint32') so MATLAB stores intmax('uint32')
추가 답변 (0개)
참고 항목
카테고리
Help Center 및 File Exchange에서 Logical에 대해 자세히 알아보기
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!