realmin

ans =

  2.2251e-308

realmin/2

ans =

  1.1125e-308

realmin*2^(-52)

ans =

  4.9407e-324

realmin*2^(-52)/2

ans =

     0

realmax

ans =

  1.7977e+308

realmax*2

ans =

   Inf

34.27-0.27

ans =

    34

format long e
34.27-0.27

ans =

    34

34.27-34

ans =

     2.700000000000031e-01

x=1e-16

x =

     1.000000000000000e-16

((1+x)-1)/x

ans =

     0

1e-8

ans =

     1.000000000000000e-08

format
(exp(x)-1)/x

ans =

     0

x=1e-8

x =

   1.0000e-08

(exp(x)-1)/x

ans =

    1.0000

format long e
(exp(x)-1)/x

ans =

     9.999999939225290e-01

x=1e-12

x =

     1.000000000000000e-12

(exp(x)-1)/x

ans =

     1.000088900582341e+00

x=1e-14

x =

     1.000000000000000e-14

(exp(x)-1)/x

ans =

     9.992007221626409e-01

x=1e-15

x =

     1.000000000000000e-15

(exp(x)-1)/x

ans =

     1.110223024625157e+00

x=1e-30

x =

     1.000000000000000e-30

(exp(x)-1)/x

ans =

     0

x = 1.49011611938477e-8

x =

     1.490116119384770e-08

(1+x)-1

ans =

     1.490116119384766e-08

x=1e-8

x =

     1.000000000000000e-08

(1+x)-1

ans =

     9.999999939225290e-09

x=1.1e-8

x =

     1.100000000000000e-08

(1+x)-1

ans =

     1.100000002196566e-08

x = 1.49011611938477e-8

x =

     1.490116119384770e-08

(1+x)-1

ans =

     1.490116119384766e-08

2^(-23)

ans =

     1.192092895507812e-07

2^-26

ans =

     1.490116119384766e-08

x=linspace(0,1,11)

x =

  Columns 1 through 2

                         0     1.000000000000000e-01

  Columns 3 through 4

     2.000000000000000e-01     3.000000000000000e-01

  Columns 5 through 6

     4.000000000000000e-01     5.000000000000000e-01

  Columns 7 through 8

     6.000000000000000e-01     7.000000000000000e-01

  Columns 9 through 10

     8.000000000000000e-01     9.000000000000000e-01

  Column 11

     1.000000000000000e+00

format
x=linspace(0,1,11)

x =

  Columns 1 through 7

         0    0.1000    0.2000    0.3000    0.4000    0.5000    0.6000

  Columns 8 through 11

    0.7000    0.8000    0.9000    1.0000

y=x^2
{Error using <a href="matlab:matlab.internal.language.introspective.errorDocCallback('mpower')" style="font-weight:bold"> ^ </a>
Inputs must be a scalar and a square matrix.
To compute elementwise POWER, use POWER (.^) instead.
} 
y=x.^2

y =

  Columns 1 through 7

         0    0.0100    0.0400    0.0900    0.1600    0.2500    0.3600

  Columns 8 through 11

    0.4900    0.6400    0.8100    1.0000

plot(x,y)
x=linspace(0,1,5);
y=x.^2;
plot(x,y)
plot(x,y,'o')
plot(x,y,'or')
figure
z=y*1e-8;
plot(x,z,'or')
m=1:10

m =

     1     2     3     4     5     6     7     8     9    10

errori=[0.1,0.02,1e-3,0.0004,0.005,1e-5,2e-6,3e-7,2e-8,1e-12]

errori =

  Columns 1 through 7

    0.1000    0.0200    0.0010    0.0004    0.0050    0.0000    0.0000

  Columns 8 through 10

    0.0000    0.0000    0.0000

plot(m,errori)
semilogy(m,errori)
plot(m,log(errori))
n=10.^(1:10);
loglog(n,errori)
diary offù