octave:2> catenaria1 octave:3> catenaria1 octave:4> catenaria1 octave:5> catenaria1 octave:6> catenaria1 octave:7> catenaria1 octave:8> catenaria1 octave:9> catenaria1 octave:10> catenaria1 octave:11> catenaria1 octave:12> catenaria1 octave:13> catenaria2 error: catenaria2: operator -: nonconformant arguments (op1 is 3x1, op2 is 251x1) error: evaluating argument list element number 1 error: called from: error: /home/accounts/personale/clrmrc90/aa1718/equazioni_differenziali/catenaria2.m at line 63, column 18 octave:13> mrif=1:11 mrif = 1 2 3 4 5 6 7 8 9 10 11 octave:14> m=3 m = 3 octave:15> mrif=11 mrif = 11 octave:16> 1:5:11 ans = 1 6 11 octave:17> m=6 m = 6 octave:18> 1:2:11 ans = 1 3 5 7 9 11 octave:19> m=3 m = 3 octave:20> 1:(mrif-1)/(m-1):mrif ans = 1 6 11 octave:21> m=6 m = 6 octave:22> 1:(mrif-1)/(m-1):mrif ans = 1 3 5 7 9 11 octave:23> range=1:12 range = 1 2 3 4 5 6 7 8 9 10 11 12 octave:24> 1:3:12 ans = 1 4 7 10 octave:25> mrif=12 mrif = 12 octave:26> 1:(mrif-1)/(m-1):mrif ans = 1.0000 3.2000 5.4000 7.6000 9.8000 12.0000 octave:27> (mrif-1)/(m-1) ans = 2.2000 octave:28> 1:2.2:12 ans = 1.0000 3.2000 5.4000 7.6000 9.8000 12.0000 octave:29> catenaria2 octave:30> catenaria2 octave:31> catenaria2 octave:32> catenaria2 warning: axis: omitting non-positive data in log plot warning: axis: omitting non-positive data in log plot octave:33> catenaria2 warning: axis: omitting non-positive data in log plot warning: axis: omitting non-positive data in log plot octave:34> catenaria2 octave:35> catenaria2 octave:36> reshape(1:9,3,3) ans = 1 4 7 2 5 8 3 6 9 octave:37> det(reshape(1:9,3,3)) ans = 0 octave:38> spdiags(reshape(1:9,3,3),-1:1,3,3) ans = Compressed Column Sparse (rows = 3, cols = 3, nnz = 7 [78%]) (1, 1) -> 4 (2, 1) -> 1 (1, 2) -> 8 (2, 2) -> 5 (3, 2) -> 2 (2, 3) -> 9 (3, 3) -> 6 octave:39> full(spdiags(reshape(1:9,3,3),-1:1,3,3)) ans = 4 8 0 1 5 9 0 2 6 octave:40> full(spdiags(reshape(1:9,3,3),[0,-1,1],3,3)) ans = 1 8 0 4 2 9 0 5 3 octave:41> h=rand(3,1) h = 0.42914 0.69702 0.49867 octave:42> x=[1;2;4;8] x = 1 2 4 8 octave:43> diff(x) ans = 1 2 4 octave:44> h h = 0.42914 0.69702 0.49867 octave:45> spdiags([[-1./h;NaN];[1/h(1);1./h(1:2)+1./h(2:3);1/h(3)];[NaN;-1./h]],-1:1,4,4) ans = Compressed Column Sparse (rows = 4, cols = 4, nnz = 3 [19%]) (2, 1) -> -2.3302 (3, 2) -> -1.4347 (4, 3) -> -2.0053 octave:46> spdiags([[-1./h;NaN],[1/h(1);1./h(1:2)+1./h(2:3);1/h(3)],[NaN;-1./h]],-1:1,4,4) ans = Compressed Column Sparse (rows = 4, cols = 4, nnz = 10 [62%]) (1, 1) -> 2.3302 (2, 1) -> -2.3302 (1, 2) -> -2.3302 (2, 2) -> 3.7649 (3, 2) -> -1.4347 (2, 3) -> -1.4347 (3, 3) -> 3.4400 (4, 3) -> -2.0053 (3, 4) -> -2.0053 (4, 4) -> 2.0053 octave:47> full(spdiags([[-1./h;NaN],[1/h(1);1./h(1:2)+1./h(2:3);1/h(3)],[NaN;-1./h]],-1:1,4,4)) ans = 2.33023 -2.33023 0.00000 0.00000 -2.33023 3.76490 -1.43467 0.00000 0.00000 -1.43467 3.44002 -2.00534 0.00000 0.00000 -2.00534 2.00534 octave:48> eig(full(spdiags([[-1./h;NaN],[1/h(1);1./h(1:2)+1./h(2:3);1/h(3)],[NaN;-1./h]],-1:1,4,4))) ans = 1.8493e-16 1.0003e+00 4.2877e+00 6.2525e+00 octave:49> full(spdiags([[NaN;-1./h],[1/h(1);1./h(1:2)+1./h(2:3);1/h(3)],[NaN;-1./h]],-1:1,4,4)) ans = 2.33023 -2.33023 0.00000 0.00000 NaN 3.76490 -1.43467 0.00000 0.00000 -2.33023 3.44002 -2.00534 0.00000 0.00000 -1.43467 2.00534 octave:50> diary off