4 Functions [10 marks]

Humidex is an index to indicate how hot the weather feels to the average person when there is some humidity. For example, if the temperature on a humid day is 30 degrees and the Humidex is 40 then it means that it feels similar to a dry day where the temperature is 40 degrees. The Humidex formula used by Environment Canada when the air temperature in degrees Celcius is \(T_a\) and the dewpoint temperature in degrees Celcius is \(T_d\) is:

\[ T_h = T_a + 0.5555\left(6.11 e^{x}-10\right) \]

where \(x = 5417.7530\left(\dfrac{1}{273.15}-\dfrac{1}{T_d + 273.15}\right)\) and \(T_h\) is the Humidex value.

Create a function that computes the Humidex value. Your function should satisfy the following constraints:

  1. it should be named humidex
  2. it should return one value Th (the Humidex value)
  3. it should have two input values Ta and Td (the air temperature and dewpoint temperature in degrees Celcius)

Note that the MATLAB function exp will compute \(e\) raised to a specified exponent.

4.1 Example usage

The exact value of h in the example below is not given to you, but it is between 30 and 35:

airTemp = 25.5;
dewpoint = 18.2;
h = humidex(airTemp, dewpoint)