필터 지우기
필터 지우기

discrete fixed point and their stability

조회 수: 4 (최근 30일)
Nehad
Nehad 2023년 11월 5일
이동: Walter Roberson 2023년 11월 5일
What is the rong with my code?
there is an error message "Conversion to logical from sym is not possible."
clc;
clear all;
syms xn xe
assume(0<xn<=1)
r=input('Enter the value of production rate','s')
f(xn)=r*xn*(1-xn);
eq=xe==subs(f,xn,xe)
display('The equilibrium points are:')
xe=solve(eq)
df=diff(r*xn*(1-xn),xn)
eq1=subs(df,xn,xe);
t=length(eq1);
eq1=double(eq1);
for i=1:t
if eq(i)>1;
fprintf('The equilibrium point %g is unstable',eq(i))
elseif eq(i)<-1;
fprintf('The equilibrium point %g is unstable',eq(i))
elseif 0<eq(i)&&eq(i)<1
fprintf('The equilibrium point %g is stable',eq(i))
else -1<eq(i)&&eq(i)<0
fprintf('The equilibrium point %g is stable',eq(i))
end
end

답변 (2개)

madhan ravi
madhan ravi 2023년 11월 5일
eq1(i)

Walter Roberson
Walter Roberson 2023년 11월 5일
이동: Walter Roberson 2023년 11월 5일
for r = -2:0.25:5
syms xn xe
assume(0<xn<=1)
f(xn)=r*xn*(1-xn);
eq=xe==subs(f,xn,xe);
fprintf('r = %g, The equilibrium points are:\n', r)
xe=solve(eq);
disp(char(xe))
df = diff(r*xn*(1-xn),xn);
eq1 = simplify(subs(df,xn,xe));
t = length(eq1);
eq1 = double(eq1);
for i=1:t
if eq1(i)>1
fprintf('r = %g, The equilibrium point %g is unstable',r,eq1(i));
elseif eq1(i)<-1
fprintf('r = %g, The equilibrium point %g is unstable',r,eq1(i));
elseif 0<eq1(i)&&eq1(i)<1
fprintf('r = %g, The equilibrium point %g is stable',r,eq1(i));
elseif -1<eq1(i)&&eq1(i)<0
fprintf('r = %g, The equilibrium point %g is stable',r,eq1(i));
else
fprintf('r = %g, failed to classify %g\n', r, eq1(i));
end
end
fprintf('\n-----\n');
end
r = -2, The equilibrium points are:
[0; 3/2]
r = -2, The equilibrium point -2 is unstable
r = -2, The equilibrium point 4 is unstable
-----
r = -1.75, The equilibrium points are:
[0; 11/7]
r = -1.75, The equilibrium point -1.75 is unstable
r = -1.75, The equilibrium point 3.75 is unstable
-----
r = -1.5, The equilibrium points are:
[0; 5/3]
r = -1.5, The equilibrium point -1.5 is unstable
r = -1.5, The equilibrium point 3.5 is unstable
-----
r = -1.25, The equilibrium points are:
[0; 9/5]
r = -1.25, The equilibrium point -1.25 is unstable
r = -1.25, The equilibrium point 3.25 is unstable
-----
r = -1, The equilibrium points are:
[0; 2]
r = -1, failed to classify -1
r = -1, The equilibrium point 3 is unstable
-----
r = -0.75, The equilibrium points are:
[0; 7/3]
r = -0.75, The equilibrium point -0.75 is stable
r = -0.75, The equilibrium point 2.75 is unstable
-----
r = -0.5, The equilibrium points are:
[0; 3]
r = -0.5, The equilibrium point -0.5 is stable
r = -0.5, The equilibrium point 2.5 is unstable
-----
r = -0.25, The equilibrium points are:
[0; 5]
r = -0.25, The equilibrium point -0.25 is stable
r = -0.25, The equilibrium point 2.25 is unstable
-----
r = 0, The equilibrium points are:
0
r = 0, failed to classify 0
-----
r = 0.25, The equilibrium points are:
[-3; 0]
r = 0.25, The equilibrium point 1.75 is unstable
r = 0.25, The equilibrium point 0.25 is stable
-----
r = 0.5, The equilibrium points are:
[-1; 0]
r = 0.5, The equilibrium point 1.5 is unstable
r = 0.5, The equilibrium point 0.5 is stable
-----
r = 0.75, The equilibrium points are:
[-1/3; 0]
r = 0.75, The equilibrium point 1.25 is unstable
r = 0.75, The equilibrium point 0.75 is stable
-----
r = 1, The equilibrium points are:
[0; 0]
r = 1, failed to classify 1 r = 1, failed to classify 1
-----
r = 1.25, The equilibrium points are:
[0; 1/5]
r = 1.25, The equilibrium point 1.25 is unstable
r = 1.25, The equilibrium point 0.75 is stable
-----
r = 1.5, The equilibrium points are:
[0; 1/3]
r = 1.5, The equilibrium point 1.5 is unstable
r = 1.5, The equilibrium point 0.5 is stable
-----
r = 1.75, The equilibrium points are:
[0; 3/7]
r = 1.75, The equilibrium point 1.75 is unstable
r = 1.75, The equilibrium point 0.25 is stable
-----
r = 2, The equilibrium points are:
[0; 1/2]
r = 2, The equilibrium point 2 is unstable
r = 2, failed to classify 0
-----
r = 2.25, The equilibrium points are:
[0; 5/9]
r = 2.25, The equilibrium point 2.25 is unstable
r = 2.25, The equilibrium point -0.25 is stable
-----
r = 2.5, The equilibrium points are:
[0; 3/5]
r = 2.5, The equilibrium point 2.5 is unstable
r = 2.5, The equilibrium point -0.5 is stable
-----
r = 2.75, The equilibrium points are:
[0; 7/11]
r = 2.75, The equilibrium point 2.75 is unstable
r = 2.75, The equilibrium point -0.75 is stable
-----
r = 3, The equilibrium points are:
[0; 2/3]
r = 3, The equilibrium point 3 is unstable
r = 3, failed to classify -1
-----
r = 3.25, The equilibrium points are:
[0; 9/13]
r = 3.25, The equilibrium point 3.25 is unstable
r = 3.25, The equilibrium point -1.25 is unstable
-----
r = 3.5, The equilibrium points are:
[0; 5/7]
r = 3.5, The equilibrium point 3.5 is unstable
r = 3.5, The equilibrium point -1.5 is unstable
-----
r = 3.75, The equilibrium points are:
[0; 11/15]
r = 3.75, The equilibrium point 3.75 is unstable
r = 3.75, The equilibrium point -1.75 is unstable
-----
r = 4, The equilibrium points are:
[0; 3/4]
r = 4, The equilibrium point 4 is unstable
r = 4, The equilibrium point -2 is unstable
-----
r = 4.25, The equilibrium points are:
[0; 13/17]
r = 4.25, The equilibrium point 4.25 is unstable
r = 4.25, The equilibrium point -2.25 is unstable
-----
r = 4.5, The equilibrium points are:
[0; 7/9]
r = 4.5, The equilibrium point 4.5 is unstable
r = 4.5, The equilibrium point -2.5 is unstable
-----
r = 4.75, The equilibrium points are:
[0; 15/19]
r = 4.75, The equilibrium point 4.75 is unstable
r = 4.75, The equilibrium point -2.75 is unstable
-----
r = 5, The equilibrium points are:
[0; 4/5]
r = 5, The equilibrium point 5 is unstable
r = 5, The equilibrium point -3 is unstable
-----

카테고리

Help CenterFile Exchange에서 Conversion Between Symbolic and Numeric에 대해 자세히 알아보기

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Translated by