how to create an input loop?

globloopprompt = 'Input value for Alpha :';
alpha = input(prompt);

if (alpha>=0.01 && alpha<=0.2)
   global alpha;
else
    error ('Incorrect alpha value');
end

I am new to matlab. Ive created this function and t all works with my corisponding code.

how would i make this code prompt the user to input another value for alpha, if they original enter a value for alpha outside the perameters.

Thank you in advance.

Answer 1

[madhan ravi]

EDITED

Avoid using global , how about the below?:

Save the below as a function with the name inputalpha.m and just call this function in the script.

function alpha = inputalpha
prompt = 'Input value for Alpha :';
alpha = input(prompt);
if (alpha>=0.01 && alpha<=0.2)
 alpha=alpha;
else
    disp('Incorrect alpha value not within bounds');
    prompt = 'Input value for Alpha :';
    alpha = input(prompt);
end
end

[vinesh vegad]

thank you.

the reason i had the global was because the alpha value that gets inputted by the user is solved on another function m-file.

is there a way of having this as well as the global intergrated into this.

thank you

[Rik]

You can further improve upon this function by making it recursive:

function alpha = inputalpha
prompt = 'Input value for Alpha :';
alpha = input(prompt);
a_lo=0.01;a_hi=0.2;%set bounds
if ~(alpha>=a_lo && alpha<=a_hi)
    clc
    fprintf('Incorrect alpha value: not within bounds\n');
    fprintf('Alpha value should be between %.2f and %.2f\n',a_lo,a_hi);
    alpha = inputalpha;%recursive call
end
end

[madhan ravi]

Thank you very much Rik , I think clc can be avoided because it may erase the previously calculated values from the script but then it depends upon the OP's wish though.

[vinesh vegad]

thank you both for the help

[Rik]

The clc is indeed a matter of context and taste. You can expand this even further by making the bounds optional input arguments:

function alpha = inputalpha(a_lo,a_hi)
prompt = 'Input value for Alpha :';
alpha = input(prompt);
if nargin~=2
    a_lo=0.01;a_hi=0.2;%set bounds
end
if ~(alpha>=a_lo && alpha<=a_hi)
    clc
    fprintf('Incorrect alpha value: not within bounds\n');
    fprintf('Alpha value should be between %.2f and %.2f\n',a_lo,a_hi);
    alpha = inputalpha(a_lo,a_hi);%recursive call
end
end

[madhan ravi]

Anytime :) @Vinesh , if the answer helped make sure to accept the answer and once again thank you very much at Rik ;-)