octave:2> 1+1 ans = 2 octave:3> 2*6 ans = 12 octave:4> 2/4 ans = 0.50000 octave:5> 3.5-0.5 ans = 3 octave:6> format long e octave:7> 3 ans = 3.00000000000000e+00 octave:8> format short octave:9> 3 ans = 3 octave:10> 3^2 ans = 9 octave:11> sqrt(2) ans = 1.4142 octave:12> format long e octave:13> sqrt(2) ans = 1.41421356237310e+00 octave:14> pi ans = 3.14159265358979e+00 octave:15> sin(pi) ans = 1.22460635382238e-16 octave:16> sin(0) ans = 0.00000000000000e+00 octave:17> cos(pi) ans = -1.00000000000000e+00 octave:18> acos(1) ans = 0.00000000000000e+00 octave:19> 5^(1/3) ans = 1.70997594667670e+00 octave:20> exp(1) ans = 2.71828182845905e+00 octave:21> e ans = 2.71828182845905e+00 octave:22> log(1) ans = 0.00000000000000e+00 octave:23> log(-1) ans = 0.00000000000000e+00 + 3.14159265358979e+00i octave:24> i ans = 0.00000000000000e+00 + 1.00000000000000e+00i octave:25> 3+4*i ans = 3.00000000000000e+00 + 4.00000000000000e+00i octave:26> 3*10^(-6) ans = 3.00000000000000e-06 octave:27> 3e-6 ans = 3.00000000000000e-06 octave:28> a=1 a = 1.00000000000000e+00 octave:29> b=2 b = 2.00000000000000e+00 octave:30> a+b ans = 3.00000000000000e+00 octave:31> c=a+b c = 3.00000000000000e+00 octave:32> realmax ans = 1.79769313486232e+308 octave:33> 1e310 ans = Inf octave:34> realmin ans = 2.22507385850720e-308 octave:35> 1e-310 ans = 9.99999999999997e-311 octave:36> 1e-315 ans = 9.99999998481684e-316 octave:37> 1e-400 ans = 0.00000000000000e+00 octave:38> a=1.7e308 a = 1.70000000000000e+308 octave:39> b=1.6e308 b = 1.60000000000000e+308 octave:40> (a+b)/2 ans = Inf octave:41> a+(b-a)/2 ans = 1.65000000000000e+308 octave:42> a/2+b/2 ans = 1.65000000000000e+308 octave:43> a a = 1.70000000000000e+308 octave:44> size(a) ans = 1.00000000000000e+00 1.00000000000000e+00 octave:45> v=[1,2,3] v = 1.00000000000000e+00 2.00000000000000e+00 3.00000000000000e+00 octave:46> size(v) ans = 1.00000000000000e+00 3.00000000000000e+00 octave:47> w=[5;6;7] w = 5.00000000000000e+00 6.00000000000000e+00 7.00000000000000e+00 octave:48> size(w) ans = 3.00000000000000e+00 1.00000000000000e+00 octave:49> v=[3e307,4e307] v = 3.00000000000000e+307 4.00000000000000e+307 octave:50> v(1) ans = 3.00000000000000e+307 octave:51> sqrt(v(1)^2+v(2)^2) ans = Inf octave:52> v(2)*sqrt((v(1)/v(2))^2+1) ans = 5.00000000000000e+307 octave:53> v=[realmax,realmax,1/realmax,1/realmax] v = Columns 1 through 3: 1.79769313486232e+308 1.79769313486232e+308 5.56268464626800e-309 Column 4: 5.56268464626800e-309 octave:54> format short octave:55> v=[realmax,realmax,1/realmax,1/realmax] v = 1.7977e+308 1.7977e+308 5.5627e-309 5.5627e-309 octave:56> prod(v) ans = Inf octave:57> w=[1/realmax,1/realmax,realmax,realmax] w = 5.5627e-309 5.5627e-309 1.7977e+308 1.7977e+308 octave:58> prod(w) ans = 0 octave:59> log(v) ans = 709.78 709.78 -709.78 -709.78 octave:60> exp(sum(log(v))) ans = 1 octave:61> x=8e-16 x = 8.0000e-16 octave:62> ((1+x)-1)/x ans = 1.1102 octave:63> x=3 x = 3 octave:64> ((1+x)-1)/x ans = 1 octave:65> x=8e-16 x = 8.0000e-16 octave:66> ((1+x)-1)/x ans = 1.1102 octave:67> 1.005-1 ans = 0.0050000 octave:68> ans ans = 0.0050000 octave:69> ans^7 ans = 7.8125e-17 octave:70> esempio4 octave:71> x x = Columns 1 through 5: 1.0000e-01 1.0000e-02 1.0000e-03 1.0000e-04 1.0000e-05 Columns 6 through 10: 1.0000e-06 1.0000e-07 1.0000e-08 1.0000e-09 1.0000e-10 Columns 11 through 15: 1.0000e-11 1.0000e-12 1.0000e-13 1.0000e-14 1.0000e-15 octave:72> y y = Columns 1 through 7: 1.05171 1.00502 1.00050 1.00005 1.00001 1.00000 1.00000 Columns 8 through 14: 1.00000 1.00000 1.00000 1.00000 1.00009 0.99920 0.99920 Column 15: 1.11022 octave:73> plot(x,y) octave:74> plot(x,y,'o') octave:75> semilogx(x,y,'o') octave:76> x x = Columns 1 through 5: 1.0000e-01 1.0000e-02 1.0000e-03 1.0000e-04 1.0000e-05 Columns 6 through 10: 1.0000e-06 1.0000e-07 1.0000e-08 1.0000e-09 1.0000e-10 Columns 11 through 15: 1.0000e-11 1.0000e-12 1.0000e-13 1.0000e-14 1.0000e-15 octave:77> y y = Columns 1 through 7: 1.05171 1.00502 1.00050 1.00005 1.00001 1.00000 1.00000 Columns 8 through 14: 1.00000 1.00000 1.00000 1.00000 1.00009 0.99920 0.99920 Column 15: 1.11022 octave:78> errore=abs(y-1) errore = Columns 1 through 5: 5.1709e-02 5.0167e-03 5.0017e-04 5.0002e-05 5.0000e-06 Columns 6 through 10: 4.9996e-07 4.9434e-08 6.0775e-09 8.2740e-08 8.2740e-08 Columns 11 through 15: 8.2740e-08 8.8901e-05 7.9928e-04 7.9928e-04 1.1022e-01 octave:79> semilogx(x,errore,'o') octave:80> loglog(x,errore,'o') octave:81> loglog(x,errore) octave:82> errore=abs(y-1)/1 errore = Columns 1 through 5: 5.1709e-02 5.0167e-03 5.0017e-04 5.0002e-05 5.0000e-06 Columns 6 through 10: 4.9996e-07 4.9434e-08 6.0775e-09 8.2740e-08 8.2740e-08 Columns 11 through 15: 8.2740e-08 8.8901e-05 7.9928e-04 7.9928e-04 1.1022e-01 octave:83> errore=abs(y-1)/1 errore = Columns 1 through 5: 5.1709e-02 5.0167e-03 5.0017e-04 5.0002e-05 5.0000e-06 Columns 6 through 10: 4.9996e-07 4.9434e-08 6.0775e-09 8.2740e-08 8.2740e-08 Columns 11 through 15: 8.2740e-08 8.8901e-05 7.9928e-04 7.9928e-04 1.1022e-01 octave:84> diary off