CS 100: Lecture L20
April 8
A [ 1 2 3 4; 5 6 7 8; 9 10 11 12]; v = A(2,:) % Same as v = [ 5 6 7 8] v = A(2,2:3) % Same as v = [6 7] v = A(:,3) % Same as v = [3; 7; 11] v = A(2:3,3) % Same as v = [7; 11] x = [10 50 20 70 40 60] v = x > 30 % Same as v = [ 0 1 0 1 1 1] u = find(v) % Same as u = [2 4 5 6] y = (x< 15) | (x > 55) % Same as y = [1 0 0 1 0 1]
Java two-dimensional arrays
The array set-up
int[][] A = { {1,2,3},{4,5,6},{7,8,9},{10,11,12}};
is the same as
int[][] A = new int[4][3]; int k = 0; for (int i=0;i< 4;i++) { for (int j=0;j< 3;j++) { k++; A[i][j] = k; } }