# Octave 3.6.2, Wed Oct 03 13:09:42 2012 CEST <achilles@achilles-TOSH>
realmax
realmin
eps
2^(-53)
a = 1
toascii('~')
% per battere "~": tenenere abbassato il tasto ALT e
% digitare 126 sul tastierino numerico
while  1 ~= 1 + a  a = a/2; end;
a
b = 1/10
for k = 1:20 b = b*11-1, end;
format long
b = 1/10
for k = 1:20 b = b*11-1, end;
help format
format bit
1/10
-1/10
eps
format
eps
eps/2*11^20
2^(-54)*11^20
% cancellazione numerica, Quarteroni-Saleri, p. 7
x = 1.e-100
((1+x)-1)/x
x = 1.e-16
((1+x)-1)/x
x = 1.e-8
((1+x)-1)/x
x = 1.e-12
((1+x)-1)/x
x = 1.e-14
((1+x)-1)/x
x = linspace(1-1.e-8, 1+1.e-8);
y = (x-1).^7;
plot(x,y)
p = poly([1 1 1 1 1 1 1])
yy = polyval(p,x);
hold on
plot(x,yy,'r')
realmax + 1
realmax + 2
realmax + 100
2*realmax
0/0
4:7
4:2:7
4:0.5:7
7:-0.5:4
for k = 1:4 k^2, end
k=1
while k^2<30 k^3, k=k+1; end
quit
