octave:2> n=0
n = 0
octave:3> xw = gauss (n + 1, r_jacobi (n + 1, 0, 0));
warning: /home/accounts/personale/clrmrc90/aa1819/calcolo_numerico2/r_jacobi.m: possible Matlab-style short-circuit operator at line 17, column 18
warning: /home/accounts/personale/clrmrc90/aa1819/calcolo_numerico2/r_jacobi.m: possible Matlab-style short-circuit operator at line 17, column 10
octave:4> xw
xw =

   0   2

octave:5> n=1
n =  1
octave:6> xw = gauss (n + 1, r_jacobi (n + 1, 0, 0));
octave:7> xw
xw =

  -0.57735   1.00000
   0.57735   1.00000

octave:8> 1/sqrt(3)
ans =  0.57735
octave:9> n=2
n =  2
octave:10> xw = gauss (n + 1, r_jacobi (n + 1, 0, 0));
octave:11> xw
xw =

  -7.7460e-01   5.5556e-01
  -4.5103e-17   8.8889e-01
   7.7460e-01   5.5556e-01

octave:12> fun=@ sin(x);
error: 'x' undefined near line 1 column 11
error: evaluating argument list element number 1
octave:12> fun=@(x) sin(x);
octave:13> fun=@(x) sin(x)+cos(x);
octave:14> integralgl(fun,1)
x =

  -0.57735
   0.57735

w =

   1   1

ans =  1.6758
octave:15> integralgl(fun,2)
x =

  -0.77460
   0.00000
   0.77460

w =

   0.55556   0.88889   0.55556

ans =  1.6830
octave:16> integralgl(fun,3)
x =

  -0.86114
  -0.33998
   0.33998
   0.86114

w =

   0.34785   0.65215   0.65215   0.34785

ans =  1.6829
octave:17> integralgl(fun,4)
x =

  -0.90618
  -0.53847
   0.00000
   0.53847
   0.90618

w =

   0.23693   0.47863   0.56889   0.47863   0.23693

ans =  1.6829
octave:18> integralgl(fun,5)
error: Formula di quadratura Gauss-Legendre non definita per n > 4
error: called from:
error:   /home/accounts/personale/clrmrc90/aa1819/calcolo_numerico2/integralgl.m at line 7, column 3
octave:18> integralgl(fun,0)
x = 0
w =  2
ans =  2
octave:19> integralgl(fun,4)
x =

  -0.90618
  -0.53847
   0.00000
   0.53847
   0.90618

w =

   0.23693   0.47863   0.56889   0.47863   0.23693

ans =  1.6829
octave:20> quad(fun,-1,1)
ans =  1.6829
octave:21> format long e
octave:22> quad(fun,-1,1)
ans =    1.68294196961579e+00
octave:23> integralgl(fun,4)
x =

  -9.06179845938664e-01
  -5.38469310105683e-01
   0.00000000000000e+00
   5.38469310105683e-01
   9.06179845938664e-01

w =

 Columns 1 through 3:

   2.36926885056189e-01   4.78628670499366e-01   5.68888888888889e-01

 Columns 4 and 5:

   4.78628670499366e-01   2.36926885056189e-01

ans =    1.68294197040719e+00
octave:24> integralglab(fun,4,-1,1)
ans =    1.68294197040719e+00
octave:25> integralglab(fun,4,0,pi)
ans =    2.00000011028447e+00
octave:26> integralglab(fun,4,0,2*pi)
ans =   -1.93542945143288e-04
octave:27> fun
fun =

@(x) sin (x) + cos (x)

octave:28> integralglab(fun,4,0,2*pi)
ans =   -1.93542945143288e-04
octave:29> integralglab(fun,8,0,2*pi)
ans =   -4.49909554056660e-12
octave:30> integralglab(fun,12,0,2*pi)
ans =    3.03923552991137e-15
octave:31> fun = @(x) sin (x .^ 2);
octave:32> a = -10;
octave:33> b = 10;ù
error: invalid character 'Ã' (ASCII 195) near line 1, column 9
parse error:

  syntax error

>>> b = 10;ù
           ^

octave:33> b = 10;
octave:34> [q, x] = integralglabadat (fun, a, b, 1e-2);
octave:35> plot(x, fun (x), x, zeros (size (x)), 'o')
octave:36> E = abs (q - quad (fun, a, b))
E =    3.23974141351879e-04
octave:37> diary off