erlang.m

爱尔兰仿真程序

% function [N,B,A] = Erlang 
% 2006-11-13
% 爱尔兰呼损表

clear;
clc;
N = 1 : 10;
% B = 0.0001 : 0.0001: 0.0020;
B = [0.01 0.05 0.1 0.5 1.0 2 5 10 15 20 30 40];
B = B./100;
A = zeros( length(N) , length(B) );

for i = 1 : length(N)
    sym x;
    str ='';
    for k = 0 : N(i)-1
        str = strcat( str, '(x^',num2str(k),')/',num2str(factorial(k)),'+' );
    end
    str = strcat( str, '(x^',num2str(N(i)),')/',num2str(factorial(N(i))) );
    str = strcat( num2str(factorial(N(i))) ,'*(', str ,')');
    for j = 1 : length(B)
        eqution = strcat( 'x^', num2str(N(i)) ,'/(', str,')-',num2str(B(j)) );
        S = solve (eqution);
        % 取大于零的实数
        for m = 1:length(S)
            if isreal(S(m)) 
                result = str2double( char(S(m)) );
                if  result > 0
                    A(i,j) = result;
                end
            end
        end
    end
    clear x;
end
% 显示程序
% 显示B
MAX = 10;
str = repmat( '_' , 1 , 5 + MAX * length(B) );
disp(str)

str = '|N/B|';
for i =1 :length(B)
    str_B = num2str(B(i));
    temp = repmat( ' ',1,MAX - length(str_B));
    str = [str temp str_B];
end
disp(str)
str = repmat( '-' , 1 , 5 + MAX * length(B) );
disp(str)
% 显示A

for i = 1 : length( A(:,1) )
    temp_N = num2str(i);
    str = repmat( ' ',1,3 - length(temp_N));
    str = ['|' str temp_N '|'];
    for j = 1 : length( A(1,:) )
        str_A = num2str( A(i,j) );
        if length(str_A)>= 6
            str_A = str_A( 1:6 );
        end
        temp = repmat( ' ',1,MAX - length(str_A));
        str = [str temp str_A];
    end
    disp(str)
    if mod(i,5)==0
        disp(sprintf('\n'))
    end
end
str = repmat( '-' , 1 , 5 + MAX * length(B) );
disp(str)