Creating a set range for a function

Hi guys,

Im trying to create a if fucnction where my equation works for a set range of x values.

My code at the moment:

x = (mydata);

if (x < 3) && (x > 25)

windTurbineRotorModel(x == 0);

elseif (3 < x) && (x < 11)

windTurbineRotorModel = (0.042)*(1/2)*(1.23)*pi()*((171/2)^3)*(x).^2;

elseif (11 < x) && (x < 25)

windTurbineRotorModel = (0.042)*(1/2)*(1.23)*pi()*((171/2)^3)*(x).^2;

end

Thanks

Answer 1

[Alan Stevens]

(x < 3) && (x > 25)

An individual element of x can't be both less than 3 and greater than 25 at the same time.

If here are many values of x (as is likely), then do the tests element by element. e.g. something like:

for i = 1:numel(x)
    if (x(i) < 3) || (x(i) > 25)
        windTurbineRotorModel(x == 0);
    elseif  (3 < x(i)) && (x(i) < 11)
        windTurbineRotorModel = (0.042)*(1/2)*(1.23)*pi()*((171/2)^3)*(x(i)).^2;
    elseif (11 < x(i)) && (x(i) < 25)
        windTurbineRotorModel = (0.042)*(1/2)*(1.23)*pi()*((171/2)^3)*(x(i)).^2;
    end   
end

[Sebastian Sunny]

That makes alot more sense thank you

but in your code what does te numel(x) mean?

[Alan Stevens]

numel(X) is the number of elements in X.