How can i assign variable in program.

a = [a1 a2 a3 a4 a5 a6 a7 a8 a9 a10 a11 a12 a13 a14 a15 a16 a17 a18 a19 a20];
assignin('base','a1',x(1));
assignin('base','a2',x(2));
assignin('base','a3',x(3));
assignin('base','a4',x(4));
assignin('base','a5',x(5));
assignin('base','a6',x(6));
assignin('base','a7',x(7));
assignin('base','a8',x(8));
assignin('base','a9',x(9));
assignin('base','a10',x(10));
assignin('base','a11',x(11));
assignin('base','a12',x(12));
assignin('base','a13',x(13));
assignin('base','a14',x(14));
assignin('base','a15',x(15));
assignin('base','a16',x(16));
assignin('base','a17',x(17));
assignin('base','a18',x(18));
assignin('base','a19',x(19));
assignin('base','a20',x(20));
x

[Stephen23]

In most cases assignin should be avoided for more effiicent ways of passing data between workspaces. The documentation states " Best Practice: Passing Arguments The most secure way to extend the scope of a function variable is to use function input and output arguments, which allow you to pass values of variables."

Source: http://www.mathworks.com/help/matlab/matlab_prog/share-data-between-workspaces.html

Numbered variables are a sign that you are doing something wrong.

http://www.mathworks.com/matlabcentral/answers/196952-how-to-create-new-variables-in-batches-with-strcat

https://www.mathworks.com/matlabcentral/answers/304528-tutorial-why-variables-should-not-be-named-dynamically-eval

Answer 1

[Walter Roberson]

You use x but you do not define it.

[Triveni]

I want random variable during optimization using fminunc. Can you help me how can i generate random variable during optimization??

[Walter Roberson]

Using a random variable would result in a discontinuity, which fminunc() is not designed to handle.

Your question is not clear as to whether you want to use a random variable, or a value randomly selected from a list of potential values. If you want to select randomly from the variable named x then

random_x = x(randi(numel(x));

You also need to read http://www.mathworks.com/help/matlab/math/parameterizing-functions.html