pass double symbolic expression to paretosearch

hi at all.

need to pass two symbolic expression that i must try to minimize with pareto search.

with matlabFunction i turn the symbolic expression to matlab numeric function but there is no way to pass this two function to paretosearch.

Can anyone please help me with simple example?

i reproduce it for me .

thank at all

Answer 1

[Alan Weiss]

It depends on how you created your symbolic expressions.

• If you have two expressions, say obj1 and obj2, then two runs of matlabFunction returns two function handles, say funobj1 and funobj2. You can pass these to paretosearch by using the handle

twoobj = @(x)[funobj1(x),funobj2(x)];
sol = paretosearch(twoobj,2,...))

• If you have a 2-D row vector output to your objective function named obj, then matlabFunction returns a function handle funobj that is all ready for paretosearch:

sol = paretosearch(funobj,2,...)

If this doesn't work for you, please ask again with more detail, such as exactly which size inputs and outputs your functions expect, how you call matlabFunction, and how you call paretosearch.

Alan Weiss

MATLAB mathematical toolbox documentation

[Davide Di Luzio]

hi Alan thanks for your reply.

i have to function : for example obj1 and obj2 that are symbolic function

then i called for each one matlabFunction in this way

fp1=matlabFunction(obj1,{x})

to receive an output similar to @in1....in1(1,:)

with this type of variable

so if i must pass this toparetosearch i must write this :

twoobj = @(in1)[fp1(in1), fp2(in1)]

the variable in1 is automatic assigned from matlab.

this because my first way with subs to try to substitute x1,x2,x3 with x(1),x(2),x(3) didn't work

[Walter Roberson]

Use the 'vars' option to matlabFunction with a cell array

'vars', {[x]}

[Davide Di Luzio]

already tried but matlab automatically create in1 variable.

suddenly post my code

[Walter Roberson]

twoobj = @(in1)[fp1(in1), fp2(in1)]

Yes. Is that a problem?

If you matlabFunction([obj1, obj2], 'vars', {x}) then it will create appropriate code.

[Davide Di Luzio]

is not a problem but i would know where is my error. even if it works.

can you precisely explain what [obj1, obj2] do ?

thank you

[Walter Roberson]

It is not clear what error you are encountering?

[obj1, obj2] for symbolic expressions obj1 and obj2 simply creates a row vector of the two expressions. When you matlabFunction the results, MATLAB would create an anonymous function that built a row vector of results. (In some cases you need a column vector, in which situation use [obj1;obj2]

[Davide Di Luzio]

thx at all