Activity 06: Functions

Solve the following problems.

See https://asu-compmethodsphysics-phy494.github.io/ASU-PHY494/2021/02/04/04_Python_3/ for help.

Create functions

1. create a file myfuncs.py
2. add a Heaviside function heaviside() to the file
3. add a function fahrenheit2kelvin() to convert from Fahrenheit to Kelvin
4. add a function kelvin2celsius() to convert from Kelvin to Celsius (subtract 273.15).

Test your functions yourself in ipython:

In [1]: %run myfuncs.py
In [2]: heaviside(5)
Out[2]: 1.0
In [3]: fahrenheit2kelvin(100)
Out[3]: 310.92777777777775
In [4]: kelvin2celsius(300)
Out[4]: 26.850000000000023
In [5]: kelvin2celsius(fahrenheit2kelvin(100))
Out[5]: 37.77777777777777

Plotting the step function

Create a program step_plot.py that

1. defines the Heaviside step function heaviside(x) (you can copy your code from the previous problem)
2. generates a list of x values x_values = [-4, -3.5, -3, ..., 0, 0.5, 1, 1.5, ... 4];
3. evaluates heaviside(x) for all x values and stores the results in a list y_values;
4. prints the lists of x and y = heaviside(x) values; it should look like

    -4.0 0.0
    -3.5 0.0
    ...
    3.5 1.0
    4.0 1.0 
   

BONUS: You can plot the Heaviside function with the plot() function from matplotlib:

import matplotlib.pyplot as plt

plt.plot(x_values, y_values, '-o', color="red", linewidth=2)
plt.show()

(This is not tested.)

BONUS: Function arguments

Add to your file myfuncs.py a function area() that

• takes two numbers as required arguments
• has an optional keyword argument scale that defaults to 1
• has an optional keyword argument offset that defaults to 0
• computes the (scaled) area of a rectangle A = scale * (x * y + offset)

(Note: This is a BONUS problem. This means that the points for this problem are not required to get full marks. If you do not solve this problem then your workflow badge will show a failure with 18/20 points. However, the maximum number of points as set in Canvas are set to 18, so you will still score full points. You cannot score more than 18 points in Canvas.)