Hands-on exercise – Working with Scientific Data

Put the lesson Working with Scientific Data into practice by writing a program yourself.

Young's modulus from test data

The problem

The starter code contains the elastic part of a tensile test as CSV text: strain in the first column and stress in MPa in the second.

In the elastic region, stress = E × strain, so the slope of a straight-line fit is Young's modulus E.

Your program should

Load the data with np.loadtxt(), skipping the header.
Print the number of data points.
Fit a straight line to stress against strain with np.polyfit().
Print Young's modulus in GPa with 1 decimal place.

Expected output

Data points: 6
Young's modulus: 70.3 GPa

Your solution

Write your program below and press Run. Each run is checked against the expected output.

main.py

Loading editor…

or press Ctrl + Enter in the editor

Output

Press Run to see what your program prints.

Need help?

One possible solution. Other programs that print the same output are correct too.

solution.py

import ioimport numpy as npcsv_text = """strain,stress_mpa0.0000,00.0010,710.0020,1390.0030,2110.0040,2800.0050,352"""data = np.loadtxt(io.StringIO(csv_text), delimiter=",", skiprows=1)strain = data[:, 0]stress = data[:, 1]print("Data points:", len(data))slope, intercept = np.polyfit(strain, stress, 1)print(f"Young's modulus: {slope / 1000:.1f} GPa")

Output

Data points: 6 Young's modulus: 70.3 GPa