How to import array into fsolve function

For asking my question I desined a very simple function:

function F = solve(x,a)
F(1) = x(1)-a;
F(2) = x(2)-3;
end

I want to solve the above function with fsolve function for an array (I know that the above function is super simple but I want to find out how to solve using fsolve for an array)

a = [1, 2];

fun = @(x)solve(x,a);
x0 = [1, 1];
x = fsolve(fun, x0)

When a is not a matrix, there is no problem but when a would be a = [1, 2] or any other matrix there is an error.

Could we do it using matlab?

The problem can be solved like the following using a for loop but can I do it without for loop?

a = [1, 2];
for i=1:2
fun = @(x)solve(x,a(i));
x0 = [1, 1];
x = fsolve(fun, x0)

x1(i) = x(1)
x2(i) = x(2)
end

Answer 1

[Walter Roberson]

You have three choices:

• for loop
• hidden for loop using arrayfun (convenient)
• redesign the way you create your function to be able to effectively calculate a number of different functions at the same time, and then use a single fsolve call.

For example you could pass in a vector of a values and use something like

F = [x(2) -  3;
     x(:) - a(1:7);
     3*x(6:7) + x(2:3) - a(8:9)]

and so calculate a number of different things in parallel.

[octa]

Thanks, but I can't understand your code. The second and third line are not clear (I only have x(1) and x(2) but you tried to consider x as 1*7 dimension, and a as 1*9 dimension

and

how can I do it using "arrayfun"?