Choosing between different input parameters in the same script

Hi , I need help with my matlab script. This script is mainly divided into two parts. In the first one I declare the input parameters for my model and in the second one the script does all the "simulation" , is a grain growth and recrystallization model for stainless steel (and I do not need to modify this part, is fixed). I need to change my input parameters (3 simple variables, that is different for each steel) in a clever way. Now I am doing this task commenting all the variable that I do not need. How can I do this ? Moreover this this script also run in a GUI and the I would like to use a pop up menu for selecting this different input. Thanks in advance

e= 0.20;    
Ntot = 1e11;
Drho0= 1e8;
%--------------%
e= 0.40;
Ntot = 2e11;
Drho0= 1e9;

Answer 1

[Stephen23]

Use switch and some appropriate names for those steel types:

switch steel_type
    case 'type1'
        e = 0.20;
        Ntot = 1e11;
        Drho0 = 1e8;
    case 'type2'
        e = 0.40;
        Ntot = 2e11;
        Drho0 = 1e9;
end

[Giuseppe Napoli]

Amazing. I dont know this function and it is perfect for my script. Thanks again

Answer 2

[KSSV]

How about this?

iwant = 1 ;

if iwant ==1
    e= 0.20;
    Ntot = 1e11;
    Drho0= 1e8;
elseif iwant ==2
    %--------------%
    e= 0.40;
    Ntot = 2e11;
    Drho0= 1e9;
    %--------------%
elseif iwant ==3
    e= 0.30;
    Ntot = 2e12;
    Drho0= 1e10;
end

[Giuseppe Napoli]

Thanks, I will try this.