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a = [1 1 1; 2 2 2; 3 3 3];
b = [1 2 3];
How can I call one function to get a vector v[i] = a[b[i],i]?
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The most common way is to explicitly specify the indices of the elements. For example, to access a single element of a matrix, specify the row number followed by the column number of the element. e is the element in the 3,2 position (third row, second column) of A .
Similar to vectors, you can use the square brackets [ ] to select one or multiple elements from a matrix. Whereas vectors have one dimension, matrices have two dimensions. You should therefore use a comma to separate the rows you want to select from the columns.
x = A ./ B divides each element of A by the corresponding element of B . The sizes of A and B must be the same or be compatible. If the sizes of A and B are compatible, then the two arrays implicitly expand to match each other.
v = a(sub2ind(size(a), b, 1:length(b)))
sub2ind transforms subscripts into a single index.
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