flplot.m

来自「SFLOP simulates a floating point operat」· M 代码 · 共 44 行

       
%
%  PURPOSE:
%  FLPLOT  plots all positive floating point numbers for 
%  a given base, exponent range and mantissa length
%
%
%  Matthias Heinkenschloss
%  Department of Computational and Applied Mathematics
%  Rice University
%  Feb 12, 2002
%
%

disp('  Plot of all positive floating point numbers                 ')
disp('             0       -1      -2            -(t-1)   e         ')
disp('  x = ( d * b + d * b + d * b +..... d   * b  )  * b  ,       ')
disp('         0       1       2            (t-1)                   ')
disp('                                                              ')
disp('  where   b =2  is the base and  e  in [ e_min, e_max ] is the exponent. ')

b = 2;
t     = input(' Mantissa length t = ');
e_min = input(' lower boundary of exponent range e_min = ');
e_max = input(' upper boundary of exponent range e_max = ');


x = [0];
k = 1;
for e = e_min:e_max
    k = k+1;
    x = [x, b^e];
    while( x(k) < b^(e+1)*(1-b^(-t)) )
        k = k+1;
        x = [x, x(k-1) + b^(e-(t-1))];
    end
end
    
disp(x')
        
plot(x,zeros(size(x)),'r+' )
title(['positive floating point numbers (\beta = 2, t=',int2str(t),...
       ' e_{min} =', int2str(e_min),' e_{max} =', int2str(e_max),')'])