Defining parameters in a function

• Hi. I want to find the minimum of a function using parameters I've defined elsewhere. i.e.

a = 2; b = 3;

[x fval] = fminbnd('a*x^2+b',1,10)

How can this be done?

Answer 1

[Paulo Silva]

clf
a = 2; b = 3;
fun=@(x,a,b)a*x^2+b;
[x fval] = fminbnd(@(x) fun(x,a,b),1,10)
%lets see if the values are correct
ezplot('2*x^2+3')
hold on
plot(x,fval,'r*')
text(x,fval,'\leftarrow Minimum','FontSize',18')

Be aware that the interval [1 10] for x isn't a good choice like you can see in the figure, the value you get from fminbnd isn't the minimum of the function, change the interval to [-2 2] and you get the minimum of the function.

[Frank]

Thanks