change numbers in array

Say that an input ask you to input numbers

Ex: [50 -6 14]

, but it won't allow you to enter numbers equal to or less than zero.

How do I build an if statement that would allow me to replace the negative or zero number?

Reminder: all the inputs are placed all in one input( at the same time); not seperately.

Answer 1

[JESUS DAVID ARIZA ROYETH]

you can do this:

 array = input('Please enter array');
array(array<=0)=nan

or this :

a=true;
while a
array = input('Please enter array with  numbers >= 0');
a=sum(array<0)>0;
end

edit:

a=false;
while not(a)
array = input('Please enter array 1x3:');
a=isequal(size(array),[1,3]);
end
for k=1:3
    if array(k)<=0
        a=true;
        while a
            newvalue=input(num2str(k,'Please replace index %i, because must be greater than 0'));
            a=newvalue<=0;
        end
        array(k)=newvalue;
    end
end
disp(array);

[Nathan Formby]

To be more specific. The task is to enter 1 array with 1 row and 3 columns. If one of the numbers is equal to or less than zero it must be replaced.

[JESUS DAVID ARIZA ROYETH]

here:

a=false;
while not(a)
array = input('Please enter array 1x3:');
a=isequal(size(array),[1,3]);
end
for k=1:3
    if array(k)<=0
        a=true;
        while a
            newvalue=input(num2str(k,'Please replace index %i, because must be greater than 0'));
            a=newvalue<=0;
        end
        array(k)=newvalue;
    end
end
disp(array);