MATLAB: Do I get this result?

if statementMATLAB

Hello
I have a problem with this code
k=2*A+3*B
if k<3.65
    fr='inf'
elseif 3.65<k<=4.35
    fr='moy'
elseif k>4.35
    fr='sup'
end
why i get this result 'moy'?? it must be 'sup'
k =
      6.4582
fr =
moy
Can you help me to correct this code.

Best Answer

The below line is the culprit:
   elseif 3.65<k<=4.35
Specifying inequalities in matlab isn't done in the same notation as you might when writing them. If you need to find when a value is between an upper and lower bound, do something like this:
    elseif 3.65 <= k && k <= 4.35
The way you have it, matlab evaluates the statement from left to right. So, if k = 6.4582, these will be the steps matlab performs:
1. (3.65 < k) <= 4.35
2. (1) <= 4.35
3. 1
Because the expression in parenthesis is true, it evaluates to "1." This leaves 1 <= 4.35, which will also return 1. But your value was 6.4582, meaning the code didn't do what you intended!
Instead, include each condition in your if statement, separating them with && symbols.
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