Can someone help with my syntax error

Question

Brendan Clark 2021-4-4

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/792077-can-someone-help-with-my-syntax-error

评论： Brendan Clark 2021-4-4

I'm having trouble getting this to iterate through all rows of my matrix.

the goal is simply to be able to input a random matrix, and use 2 for loops to have the program locate and fprint the row and column index for all occurences of the integer. I can't use the find function, yes this is homework.

4 个评论
显示 2更早的评论隐藏 2更早的评论

Walter Roberson 2021-4-4

As a guideline... beyond approximately five short lines, people are not going to be willing to type in code to test with. And even with short lines, if the question has to do with syntax errors, it is best to post the exact code as there could be hidden characters or something subtle that is important.

Brendan Clark 2021-4-4

Thats good information to have, I appreciate the information and I'll make sure my future posts follow these guidelines.

请先登录，再进行评论。

请先登录，再回答此问题。

Answer 1

Image Analyst 2021-4-4

1
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/792077-can-someone-help-with-my-syntax-error#answer_666792

在 MATLAB Online 中打开

We can't run or fix an image. But this will be useful to you instead of x and y

[rows, columns] = size(a)
for col = 1 : columns
    for row = 1 : rows
        if a(row, col) == 5
            fprintf('a = %f at row=%d and column = %d.\n', a(row, col), row, col);
        end
    end
end

Or vectorized, using the find() function, which you're not allowed to use for this homework problem:

matchingMap = a == 5;
[matchingRows, matchingColumns] = find(matchingMap)

0 个评论
显示 -2更早的评论隐藏 -2更早的评论

请先登录，再进行评论。

Answer 2

KSSV 2021-4-4

0
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/792077-can-someone-help-with-my-syntax-error#answer_666432

在 MATLAB Online 中打开

If A is your array to count number of times a number n (say 5) appears, follow:

tol = 10^-5 ;
idx = abs(A-n)<=tol ; 
nnz(idx(:))

1 个评论
显示 -1更早的评论隐藏 -1更早的评论

Brendan Clark 2021-4-4

I don't think I phrased that well, the main goal is to use a set of for loops to find the row and column index for each occurence. The code I originally posted works for one row, but not multiple, I just need to get it to iterate through any avaialable rows.

请先登录，再进行评论。

Answer 3

Walter Roberson 2021-4-4

0
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/792077-can-someone-help-with-my-syntax-error#answer_666487

在 MATLAB Online 中打开

for b = 1 : numel(a)

Caution: length() is not the same as width() . If the array has more rows than columns, then the length() would be the number of rows, same as height()