accepting values into an array, then accepting new values by shifting left
조회 수: 2 (최근 30일)
이전 댓글 표시
I am calling a function in a different m file. I want this function to write newValues into an array. After 7 entries, the newValues need to be added to the end of the array and then shifted left in order to keep the values in order. Example: values accepted in the array are [1 2 3 4 5 6 7]. The new value is 8 which makes the array have values [2 3 4 5 6 7 8]. This is what I have so far....
function arrayWithLatestValues = fn_updateArray(newValue)
persistent A;
A = [A(2:end) newValue];
arrayWithLatestValues = A;
end
this is my output im getting:
0 0 0 0 0 0 0
0 0 0 0 0 0 0
0 0 0 0 0 0 0
0 0 0 0 0 0 0
0 0 0 0 0 0 0
0 0 0 0 0 0 0
0 0 0 0 0 0 0
0 0 0 0 0 0 0
0 0 0 0 0 0 0
0 0 0 0 0 0 0
0 0 0 0 0 0 0
0 0 0 0 0 0 0
댓글 수: 0
채택된 답변
possibility
2018년 2월 10일
편집: possibility
2018년 2월 10일
I'm guessing it is because of the persistent statement. Quote from the statement explanation:
" If the persistent variable does not exist the first time you issue the persistent statement, it will be initialized to the empty matrix."
If you have the vector as an input to the function, I believe the problem will be solved.
function arrayWithLatestValues = fn_updateArray(newValue,A)
A = [A(2:end) newValue];
arrayWithLatestValues = A;
end
추가 답변 (1개)
Stephen23
2018년 2월 10일
편집: Stephen23
2018년 2월 10일
function outVec = fn_updateArray(newValue)
persistent newVec;
newVec = [newVec(max(1,end-5):end),newValue];
outVec = newVec;
end
and tested:
>> fn_updateArray(1)
ans = 1
>> fn_updateArray(2)
ans =
1 2
>> fn_updateArray(3)
ans =
1 2 3
>> fn_updateArray(4)
ans =
1 2 3 4
>> fn_updateArray(5)
ans =
1 2 3 4 5
>> fn_updateArray(6)
ans =
1 2 3 4 5 6
>> fn_updateArray(7)
ans =
1 2 3 4 5 6 7
>> fn_updateArray(8)
ans =
2 3 4 5 6 7 8
>> fn_updateArray(9)
ans =
3 4 5 6 7 8 9
>>
참고 항목
카테고리
Help Center 및 File Exchange에서 Matrix Indexing에 대해 자세히 알아보기
제품
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!