Why reading and writing data is fundamental in MATLAB - See It in Action

Why reading and writing data is fundamental

📖 Scenario: You are working on a simple project to manage student scores. You need to read scores from a file, process them, and save the results back to a file. This is a common task in many real-world projects where data comes from external sources and results need to be stored.

🎯 Goal: Build a MATLAB program that reads student scores from a file, calculates the average score, and writes the average to a new file.

📋 What You'll Learn

Read data from a text file called scores.txt

Calculate the average of the scores

Write the average score to a file called average.txt

💡 Why This Matters

🌍 Real World

Many real-world programs need to read data from files, process it, and save results. For example, analyzing sales data, processing sensor readings, or managing student grades.

💼 Career

Understanding file input/output is essential for data analysis, software development, and automation tasks in many jobs.

1

Create the data file scores.txt

Create a text file called scores.txt with these exact scores on separate lines: 85, 90, 78, 92, 88.

MATLAB

% Create the file 'scores.txt' with the given scores
% Your code here

Need a hint?

Use fopen to open the file for writing, fprintf to write each score on a new line, and fclose to close the file.

2

Read the scores from scores.txt

Open the file scores.txt for reading and read all the scores into a variable called scores using fscanf.

MATLAB

fileID = fopen('scores.txt','w');
fprintf(fileID, '85\n90\n78\n92\n88\n');
fclose(fileID);

% Open 'scores.txt' for reading and read scores into 'scores'
% Your code here

Need a hint?

Use fopen with 'r' to read, fscanf with '%d' to read integers, and fclose to close the file.

3

Calculate the average score

Calculate the average of the scores stored in the variable scores and save it in a variable called averageScore.

MATLAB

fileID = fopen('scores.txt','w');
fprintf(fileID, '85\n90\n78\n92\n88\n');
fclose(fileID);

fileID = fopen('scores.txt','r');
scores = fscanf(fileID, '%d');
fclose(fileID);

% Calculate the average score and store in 'averageScore'
% Your code here

Need a hint?

Use the mean function to calculate the average of the vector scores.

4

Write the average score to average.txt

Open a new file called average.txt for writing and write the text 'Average score: ' followed by the value of averageScore using fprintf. Then close the file. Finally, print the exact text Average score: 86.6 to the MATLAB console.

MATLAB

fileID = fopen('scores.txt','w');
fprintf(fileID, '85\n90\n78\n92\n88\n');
fclose(fileID);

fileID = fopen('scores.txt','r');
scores = fscanf(fileID, '%d');
fclose(fileID);

averageScore = mean(scores);

% Write the average score to 'average.txt' and print it
% Your code here

Need a hint?

Use fprintf with format 'Average score: %.1f' to write and print the average with one decimal place.