GNU Octave, version 2.0.16 (i386-pc-linux-gnu). Copyright (C) 1996, 1997, 1998, 1999, 2000 John W. Eaton. This is free software with ABSOLUTELY NO WARRANTY. For details, type `warranty'. octave> x=2 x = 2 octave> x x = 2 octave> x; octave> x=[1 2 3] x = 1 2 3 octave> x' ans = 1 2 3 octave> A=[1 2 3; 4 5 6; 7 8 9] A = 1 2 3 4 5 6 7 8 9 octave> A' ans = 1 4 7 2 5 8 3 6 9 octave> A=rand(3) A = 0.188427 0.506368 0.499963 0.055391 0.977490 0.342723 0.735019 0.301271 0.725313 octave> b=rand(3,1) b = 0.083430 0.774729 0.539715 octave> x=inv(A)*b x = 2.2191 1.3980 -2.0854 octave> A\b ans = 2.2191 1.3980 -2.0854 octave> A*x-b ans = -1.9429e-16 -3.3307e-16 -1.1102e-16 octave> v=[1 2 3]' v = 1 2 3 octave> v+1 ans = 2 3 4 octave> v*3 ans = 3 6 9 octave> sum(v) ans = 6 octave> sum(A) ans = 0.97884 1.78513 1.56800 octave> sum(sum(A)) ans = 4.3320 octave> 1:3 ans = 1 2 3 octave> ones(3,1) ans = 1 1 1 octave> A=ones(3,1)*(1:3) A = 1 2 3 1 2 3 1 2 3 octave> A .* A' ans = 1 2 3 2 4 6 3 6 9 octave> rem(A,A') ans = 0 0 0 1 0 1 1 2 0 octave> rem(A,A')==0 ans = 1 1 1 0 1 0 0 0 1 octave> sum(rem(A,A')==0) ans = 1 2 2 octave> sum(rem(A,A')==0)==2 ans = 0 1 1 octave> find(sum(rem(A,A')==0)==2) ans = 2 3 octave> A=ones(100,1)*(1:100); octave> find(sum(rem(A,A')==0)==2) ans = Columns 1 through 16: 2 3 5 7 11 13 17 19 23 29 31 37 41 43 47 53 Columns 17 through 25: 59 61 67 71 73 79 83 89 97 octave> x x = 2.2191 1.3980 -2.0854 octave> x' * x ans = 11.227 octave> x * x' ans = 4.9244 3.1022 -4.6276 3.1022 1.9543 -2.9153 -4.6276 -2.9153 4.3487 octave> x .* x ans = 4.9244 1.9543 4.3487 octave> for i=1:10; v(i)=i*i; end octave> v v = 1 4 9 16 25 36 49 64 81 100 octave> B = [1 2 3; 4 5 6; 7 8 9] B = 1 2 3 4 5 6 7 8 9 octave> B(1,1) ans = 1 octave> B(3,3) ans = 9 octave> rows(B) ans = 3 octave> columns(B) ans = 3 octave> x x = 2.2191 1.3980 -2.0854 octave> rows(x) ans = 3 octave> columns(x) ans = 1 octave> x=1:100; octave> plot(x,x.*x) octave>