Simulink vs MATLAB scripting - Hands-On Comparison

Simulink vs MATLAB scripting

📖 Scenario: You are working on a project to analyze simple system data. You want to understand the difference between using Simulink (a graphical tool) and MATLAB scripting (writing code) to model and analyze data.

🎯 Goal: Build a small data structure in Python to represent system data, then write a script to filter and analyze it, simulating the difference between graphical Simulink modeling and MATLAB scripting.

📋 What You'll Learn

Create a dictionary with system component names and their values

Add a threshold variable to select components above a certain value

Use a dictionary comprehension to filter components above the threshold

Print the filtered dictionary to show the result

💡 Why This Matters

🌍 Real World

Engineers often use Simulink for graphical system modeling and MATLAB scripting for data analysis and automation.

💼 Career

Understanding both Simulink and MATLAB scripting helps in system design, simulation, and data-driven decision making in engineering roles.

1

Create system data dictionary

Create a dictionary called system_data with these exact entries: 'sensor1': 10, 'sensor2': 25, 'actuator1': 15, 'actuator2': 5

Simulink

# Create the system_data dictionary with given entries
# Your code here

Hint

Use curly braces {} to create a dictionary with keys and values separated by colons.

2

Set threshold value

Create a variable called threshold and set it to 12

Simulink

system_data = {'sensor1': 10, 'sensor2': 25, 'actuator1': 15, 'actuator2': 5}
# Create the threshold variable and set it to 12
# Your code here

Hint

Just assign the number 12 to the variable named threshold.

3

Filter components above threshold

Use a dictionary comprehension to create a new dictionary called filtered_data that contains only the items from system_data where the value is greater than threshold

Simulink

system_data = {'sensor1': 10, 'sensor2': 25, 'actuator1': 15, 'actuator2': 5}
threshold = 12
# Create filtered_data dictionary with items having value > threshold
# Your code here

Hint

Use dictionary comprehension syntax: {key: value for key, value in dict.items() if condition}

4

Print filtered data

Write a print statement to display the filtered_data dictionary

Simulink

system_data = {'sensor1': 10, 'sensor2': 25, 'actuator1': 15, 'actuator2': 5}
threshold = 12
filtered_data = {key: value for key, value in system_data.items() if value > threshold}
# Print the filtered_data dictionary
# Your code here

Hint

Use print(filtered_data) to show the filtered dictionary.

Practice

1. What is the main difference between Simulink and MATLAB scripting?

easy

A. Simulink uses visual blocks; MATLAB scripting uses code.

B. Simulink is only for data analysis; MATLAB scripting is for graphics.

C. Simulink runs faster than MATLAB scripting always.

D. MATLAB scripting cannot create models.

Solution

1. Step 1: Understand Simulink's approach

   Simulink builds models using visual blocks and diagrams.

2. Step 2: Understand MATLAB scripting's approach

   MATLAB scripting creates and analyzes models using code commands.

3. Final Answer:

   Simulink uses visual blocks; MATLAB scripting uses code. -> Option A

4. Quick Check:

   Visual blocks vs code = D [OK]

Hint: Simulink is visual; MATLAB scripting is text-based code [OK]

Common Mistakes:

• Thinking Simulink is only for data analysis
• Believing MATLAB scripting cannot create models
• Assuming Simulink always runs faster

2. Which of the following is the correct way to open a Simulink model named myModel using MATLAB scripting?

easy

A. open('myModel.slx')

B. sim('myModel')

C. load_system('myModel')

D. run('myModel')

Solution

1. Step 1: Recall MATLAB commands for Simulink

   The command load_system('modelName') opens the Simulink model without running it.

2. Step 2: Check other options

   open() is for files but not the recommended for Simulink models; sim() runs the model; run() is for scripts.

3. Final Answer:

   load_system('myModel') -> Option C

4. Quick Check:

   Open model = load_system() [OK]

Hint: Use load_system() to open Simulink models in MATLAB [OK]

Common Mistakes:

• Using sim() to open instead of run the model
• Using open() which may not open Simulink models properly
• Confusing run() with model opening

3. Consider this MATLAB script snippet to simulate a Simulink model:

load_system('simpleModel');
simOut = sim('simpleModel', 'StopTime', '10');
result = simOut.get('yout');
disp(result);

What does result contain?

medium

A. The model file path as a string.

B. The simulation output data from the model.

C. The simulation stop time value.

D. An error because get is not a method.

Solution

1. Step 1: Understand sim() output

   The sim() function returns a Simulink.SimulationOutput object containing simulation results.

2. Step 2: Use get() method on simOut

   simOut.get('yout') retrieves logged output data named 'yout' from the simulation.

3. Final Answer:

   The simulation output data from the model. -> Option B

4. Quick Check:

   simOut.get('yout') = simulation data [OK]

Hint: sim() returns output object; get('yout') fetches data [OK]

Common Mistakes:

• Thinking get() is invalid method
• Confusing output data with file path
• Assuming result holds stop time

4. You run this MATLAB script to simulate a Simulink model:

sim('myModel')

But you get an error: Undefined function or variable 'myModel'. What is the likely cause?

medium

A. You must open the model with load_system() before simulating.

B. The sim() function is not supported for Simulink models.

C. The model name must be a full file path string.

D. The model file 'myModel.slx' is not in the current folder or path.

Solution

1. Step 1: Understand the error message

   The error means MATLAB cannot find a model named 'myModel' in the current folder or path.

2. Step 2: Check common causes

   Usually, the model file is missing or not in the MATLAB path, causing this error.

3. Final Answer:

   The model file 'myModel.slx' is not in the current folder or path. -> Option D

4. Quick Check:

   File missing = undefined variable error [OK]

Hint: Ensure model file is in current folder or MATLAB path [OK]

Common Mistakes:

• Thinking sim() cannot run models
• Believing load_system() is required before sim()
• Assuming full path is always needed

5. You want to automate running multiple Simulink models and collect their output data using MATLAB scripting. Which approach is best?

hard

A. Write a MATLAB script that loops over model names, uses sim() to run each, and stores outputs.

B. Manually open each model in Simulink and save output files.

C. Use Simulink graphical interface to drag all models into one big model.

D. Run models one by one using the Simulink GUI and copy results manually.

Solution

1. Step 1: Identify automation needs

   Automating multiple model runs requires scripting to avoid manual work.

2. Step 2: Use MATLAB scripting capabilities

   Looping over model names and running sim() collects outputs efficiently in code.

3. Step 3: Evaluate other options

   Manual or GUI methods are slow and error-prone for many models.

4. Final Answer:

   Write a MATLAB script that loops over model names, uses sim() to run each, and stores outputs. -> Option A

5. Quick Check:

   Automation with sim() loop = best practice [OK]

Hint: Use MATLAB loops with sim() to automate multiple model runs [OK]

Common Mistakes:

• Trying to automate using only Simulink GUI
• Running models manually for many cases
• Combining models graphically instead of scripting