error with inline function , why?
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%Q3: Secant Method
close all;
clear all;
clc;
syms x;
fun = input('Give a function in x: ','s');
f = inline(fun,'x');
prompt = 'p0= ';
p0 = input(prompt);
prompt = 'p1= ';
p1 = input(prompt);
prompt= 'Enter the accuracy: ';
acc=input(prompt);
result = findRoot(f,p0,p1,acc);
fprintf('\n• The root of the equation using Secant method is = %.8f',result);
function r = findRoot(f,p0,p1,acc)
errors=[];
N=[];
Pn=[];
i=0;
sprintf('Iteration\t\tPn\t\t\tError')
p2=p1-((f(p1)*(p1-p0))/(f(p1)-f(p0)));
while(abs(p2-p1)>acc)
p0=p1;
p1=p2;
p2=p1-((f(p1)*(p1-p0))/(f(p1)-f(p0)));
err=abs(p2-p1);
errors(end+1)=err; i=i+1; N(end+1)=i;
Pn(end+1)=p1;
fprintf('\t\t\t%.0f\t\t%.8f\t%.8f\n',i,p1,err);
end
fprintf('\n• Number of iteration = %.0f',i);
r=p2;
%Error plot:
figure(1)
stem(N,errors)
xlim([0. 6])
title('Error Plot Secant method')
xlabel('n')
ylabel('|E|')
%Pn plot:
figure(2)
stem(N,Pn)
xlim([0. 6])
title('Pn -> P Plot Secant method')
xlabel('n')
ylabel('Pn')
end
3 Comments
Rik
on 10 Mar 2022
Steven Lord
on 10 Mar 2022
Please stop using inline. Use anonymous functions (potentially in conjunction with str2func) instead.
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