iteration with biscetion method

Claus Madsen

2013 3 12

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7 次查看（30 天）

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Hello i need som help with program this code. I have the following parameters in a matrix[1566,1] R, I, Q_min, Q_max, A and d. And i want to solv the eq with the biscetion methode. i want the result to come out in a matriv?

%%%%%%%%%%%%%%%%%%%%%%%%%%Parameter %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
data=xlsread('ledning.xls');
Q_min=data(:,2);
R=data(:,5)/4; % Hydraulisk radius for fuldløbende ledning
I=data(:,4);   %I=I_0 dvs. slope
A=(data(:,5)/2).^2*3.14;
M=75;
d=data(:,5);
for i=1:length(data)
Q_max(i,1)=abs(A(i,1)*M*(I(i,1)/100)^(1/2)*R(i,1)^(2/3));
end
for i=1:length(data)
    p(i,1)=Q_min(i,1)/Q_max(i,1);
end
%%%%%%%%%%%%%%%%%%%%%%%%Ligning der skal løses %%%%%%%%%%%%%%%%%%%%%%%%%%%
%Ligningen løses via biscetion metoden
f=@(y) (0.46-0.5*cos(3.14*(y/d))+0.004*cos(2*3.14*(y/d)))-(p); %delfyldningsformel
format long
%%%%%%%%%%%%%%%%%%%%%%%%Betingelser til biscetion %%%%%%%%%%%%%%%%%%%%%%%%
   eps_abs = 1e-5;
   eps_step = 1e-5; %%%%abs og step angiver hvor tæt resultaterne skal være på hinanden
   a = 0; % Initial Guess to your function such that f(a)>0.
   b = 0.2; % Initial Guess to your function such that f(b)<0.
%%%%%%%%%%%%%%%%%%%%%%%%Påbegynd loop %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
while (b - a >= eps_step || ( abs( f(a) ) >= eps_abs && abs( f(b) )  >= eps_abs ) )
    c = (a + b)/2;
    if ( f(c) == 0 )
       break;
    elseif ( f(a)*f(c) < 0 )
       b = c;
    else
       a = c;
    end
end