I wrote this code,but the plot is not what I want.how can I get the plot like below picture?

% nonlinear constraint optimization function
prob=optimproblem
x=optimvar('x','LowerBound',-10,'UpperBound',10);
y=optimvar('y','LowerBound',-10);
obj=fcn2optimexpr(@objectivefunction,x,y)
prob.Objective=obj
constr=x.*y/2+(x+2).^2+(y-2).^2/2<=2  %polynomial inequality
prob.Constraints.ellipseparabola=constr
a=4
constexp=fcn2optimexpr(@constraintfunction,x,y,a)
consr2=constexp<=2
prob.Constraints.exponentialConstr=consr2
x0.x=-3
x0.y=3
options=optimoptions(prob,'Display','iter')
[sol,fval,exitflag,output]= solve(prob,x0,"options",options)
x0.x = -3;
x0.y = 4;
[sol2,fval2] = solve(prob,x0)
fprintf("Fval = %g\nNumber of iterations = %g\nNumber of function evals = %g.\n",...
    fval,output.iterations,output.funcCount)
rng default
f = @(x,y) exp(x).*(4*x^2+2*y.^2+4*x.*y+2*y-1);
figure1
plot(sol.x,sol.y,"y*",'LineWidth',2)
hold on
plot(sol2.x,sol2.y,"r*",'LineWidth',2)
%rnge = [-5.5 -0.25 -0.25 7];
rng default
fcontour(f,'-.','LineWidth',2)
legend("nonlinear constraints problem","Location","northoutside")
hold off

% objective function 
function f=objectivefunction(x,y)
f=exp(x).*(4*x^2+2*y.^2+4*x.*y+2*y-1)
end
%constraint
function constr=constraintfunction(x,y,a)
constr=x+2*exp((y-a)/4);
end

[Star Strider]

All the exponentiations need to be vectorised —

f = @(x,y) exp(x).*(4*x^2+2*y.^2+4*x.*y+2*y-1);

↑

so:

f = @(x,y) exp(x).*(4*x.^2+2*y.^2+4*x.*y+2*y-1);

I cannot run the code, so this is my best guess as to what the problem is.

Make the same correction in the ‘f’ assignment in the ‘objectivefunction’ calculation.

.

[sogol bandekian]

the warning is solved .thank you so much. another thing is that, what can I change in this code to get one plot like this?

[Alan Weiss]

As you probably know, that plot is from this example. I gave the entire code in that example. What else do you need?

Alan Weiss

MATLAB mathematical toolbox documentation

[sogol bandekian]

i made my codes for plotting similar to what you wrote but the figure is not like yous

wher is the problem?

f = @(x,y) exp(x).*(4*x.^2+2*y.^2+4*x.*y+2*y-1);

w=@(x,y) x.*y/2+(x+2).^2+(y-2).^2/2-2;

rnge = [-5.5 -0.25 -0.25 7];

fimplicit(w,'gx') %plot implicit function with consideration constraint

axis(rnge)

hold on

fcontour(f,rnge,'-.','LineWidth',2)

plot(sol.x,sol.y,"ro",'LineWidth',2)

plot(sol2.x,sol2.y,"r*",'LineWidth',2) %Global solution

legend("nonlinear constraints problem","Location","northoutside")

hold off

[Voss]

@sogol bandekian: One difference is that you didn't specify 'LevelList',logspace(-1,1) in fcontour

f = @(x,y) exp(x).*(4*x.^2+2*y.^2+4*x.*y+2*y-1);
rnge = [-5.5 -0.25 -0.25 7];
axis(rnge)
fcontour(f,rnge,'-.','LineWidth',2,'LevelList',logspace(-1,1))

[sogol bandekian]

it is not generate local solution,why?

f = @(x,y) exp(x).*(4*x.^2+2*y.^2+4*x.*y+2*y-1);

w=@(x,y) x.*y/2+(x+2).^2+(y-2).^2/2-2;

rnge = [-5.5 -0.25 -0.25 7];

fimplicit(w,'kx-') %plot implicit function with consideration constraint

axis(rnge)

hold on

fcontour(f,rnge,'-.','LineWidth',2,'LevelList',logspace(-1,1))

plot(sol.x,sol.y,"ko",'LineWidth',2)

plot(sol2.x,sol2.y,"ro",'LineWidth',2) %Global solution

legend('nonlinear constraints problem','f Contours','Global Solution','Local Solution',"Location","northoutside")

hold off

[Voss]

It is plotting both "Local" and "Global" solutions, but they are the same, so you only see the last one plotted (one is on top of the other).

If you want the solution(s) from the example in the documentation, you should use the starting point(s) from the example in the documentation:

x0.x = -1;
x0.y = 1;
[sol2,fval2] = solve(prob,x0)

Also, you've got Local in black, Global in red (according to the comment), but then the legend labels black as Global, red as Local. Check on that.