How do i get the values of a 2D matrix based on column indices ?

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YI CHONG ONG
YI CHONG ONG 2020-9-23
评论： YI CHONG ONG 2020-9-23
I know this is a simple question, but I cant seem to find answers on this.
Given a 2D matrix of any size and a vector of indices, I want to index the elements in the matrix based on the column indices values in order.
Eg.
matrix = [1 2 3
4 5 6
7 8 9] column indices = [1,3,1]
Output = [1,6,7] -> column index 1 = 1, column index 3 = 6, column index 1 = 7

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采纳的回答

madhan ravi
madhan ravi 2020-9-23
编辑：madhan ravi 2020-9-23
Output = matrix(sub2ind(size(matrix), 1 : size(matrix, 1), column_indices))

更多回答（1 个）

Ameer Hamza
Ameer Hamza 2020-9-23
Use sub2ind()
matrix = [1 2 3
4 5 6
7 8 9];
cols = [1 3 1];
idx = sub2ind(size(matrix), 1:size(matrix, 1), cols);
matrix(idx)

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