"Array indices must be positive integers or logical values".Error in (line 17) tij_lm(l, m) = min([i(l + 1) - i(l), i(l) - i(l - 1), j(m + 1) - j(m), j(m) - j(m - 1)]) / 2;

조회 수: 1 (최근 30일)
Getting "Array indices must be positive integers or logical values". Error
Error in cross_correlation (line 17)
tij_lm(l, m) = min([i(l + 1) - i(l), i(l) - i(l - 1), j(m + 1) - j(m), j(m) - j(m - 1)]) / 2;
Heres my code, why do I get the error?
% Example data for time series i and j
i = [1, 2, 3, 4, 5];
j = [1.5, 3, 4.5];
% Call the cross_correlation function with the example data
[Cxy, Jij, tij_lm] = cross_correlation(i, j);
function [Cxy, Jij, tij_lm] = cross_correlation(i, j)
% Inputs:
% i - time series data for variable i
% j - time series data for variable j
% Compute the length of time series i and j
Si = length(i);
Sj = length(j);
% Initialize Jij and tij_lm matrices
Jij = zeros(Si, Sj);
tij_lm = zeros(Si, Sj);
% Compute Jij and tij_lm for each l and m
for l = 1:Si
for m = 1:Sj
tij_lm(l, m) = min([i(l + 1) - i(l), i(l) - i(l - 1), j(m + 1) - j(m), j(m) - j(m - 1)]) / 2;
if 0 < i(l) - j(m) && i(l) - j(m) < tij_lm(l, m)
Jij(l, m) = 1;
elseif i(l) == j(m)
Jij(l, m) = 0.5;
else
Jij(l, m) = 0;
end
end
end
% Compute the cross correlation value C(x/y)
Cxy = sum(sum(Jij));
end
  댓글 수: 2
Dyuman Joshi
Dyuman Joshi 2023년 2월 11일
Indexing in MATLAB starts with 1
When l and m are 1, l-1 and m-1 are 0, which throws the error you are receiving.
""Array indices must be positive integers ...
for l = 1:Si
for m = 1:Sj
tij_lm(l, m) = min([i(l + 1) - i(l), i(l) - i(l - 1), j(m + 1) - j(m), j(m) - j(m - 1)]) / 2;
Since I don't know what you want to do with this line of code, I can't suggest any changes.
Arif Hoq
Arif Hoq 2023년 2월 11일
i = [1, 2, 3, 4, 5];
j = [1.5, 3, 4.5];
l=1:5;
i(l) - i(l - 1)
when l=1
i(1)=1
i(1-1)= i(0) % which shows an error.
also same here
j(m) - j(m - 1)
index should be an integer.
Can you please explain what you want here? please give an example.
tij_lm(l, m) = min([i(l + 1) - i(l), i(l) - i(l - 1), j(m + 1) - j(m), j(m) - j(m - 1)]) / 2;

댓글을 달려면 로그인하십시오.

채택된 답변

Arif Hoq
Arif Hoq 2023년 2월 11일
if you start your index from 2 then, this can be one approach:
% Example data for time series i and j
i = [1, 2, 3, 4, 5];
j = [1.5, 3, 4.5];
% Call the cross_correlation function with the example data
[Cxy, Jij, tij_lm] = cross_correlation(i, j)
Cxy = 0.5000
Jij = 5×3
0 0 0 0 0 0 0 0.5000 0 0 0 0 0 0 0
tij_lm = 5×3
0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
function [Cxy, Jij, tij_lm] = cross_correlation(x, y)
% Inputs:
% i - time series data for variable i
% j - time series data for variable j
% Compute the length of time series i and j
xlength = length(x);
ylength = length(y);
% Initialize Jij and tij_lm matrices
Jij = zeros(xlength, ylength);
tij_lm = zeros(xlength, ylength);
% Compute Jij and tij_lm for each l and m
for i = 2:xlength
for j = 2:ylength
tij_lm(i, j) = min([x(i) - x(i), x(i) - x(i - 1), y(j) - y(j), y(j) - y(j - 1)]) / 2;
if 0 < x(i) - y(j) && x(i) - y(j) < tij_lm(i, j)
Jij(i, j) = 1;
elseif x(i) == y(j)
Jij(i, j) = 0.5;
else
Jij(i, j) = 0;
end
end
end
% Compute the cross correlation value C(x/y)
Cxy = sum(sum(Jij));
end

추가 답변 (0개)

카테고리

Help CenterFile Exchange에서 Tables에 대해 자세히 알아보기

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Translated by