MATLAB: How to make a conditional statement when using variables

conditional statementoperandsvariables

In my script I first defined a for loop:
for n = 1:inf                  
    a = 10^(n+1);
    b = 10*a;
so the for-loop assigns every iteration new values to my variables a and b.
Right after it I made an conditional statement:
if (a <= x)&&(x < b)
I want my value x (which I assign when activating the script) to lie between a and b. But matlab won't agree with me. It says:
Operands to the || and && operators must be convertible to logical scalar
values.
Error in palin (line 10)
if (a <= x)&&(x < b)
Though I thought values to the variables a and b were assigned earlier in the script, matlab would recognize these values. I was wrong. Does anybody has a suggestion what I could do to fix this error? I hope it is very easy to solve, so that soon someone will help me out of this. Thanks in advance.

Best Answer

I'm guessing from the error message you report that x is a vector, not a scalar. From the code snippet you show, both a and b are scalars, x should be a scalar too.
So for example, look at the following
   x = 10001;
   for n = 1:3
   a = 10^(n+1);
   b = 10*a;
   if (a <= x)&&(x < b)
      disp('yes');
   else
      disp('no');
   end
   end
Now, if you try the above with x a vector
x = 10000:10004;
You'll get the error message you are seeing.
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