Functions and 2-D Arrays

• Functions like sqrt, sin, cos that operate element-by-element on 1-D arrays work the same on 2-D arrays.

m = 10 * rand(5,4)

sqrt(sin(m))

• Functions like sum, prod that produce a scalar result from a 1-D array produce a 1-D array result when applied to a 2-D array. The function is applied to columns of the 2-D array.

a = [1 2 3; 4 5 6; 7 8 9; 10 11 12]

sum(a) -- 22 26 30

• To apply these functions to rows in a 2-D array, transpose the array with the quote operator.

sum(a�) -- 6 15 24 33

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