034IN "Fundamentals of Automatic Control" - Introduction to MATLAB/Simulink - Solving Exercises on MATLAB Programming

Table of Contents

Exercise: Scripts Assignment Solution Exercise: Scalars and Math Operations Assignment Solution Exercise: Math and Vector Operations Assignment Solution Exercise: Vectors and Matrices Assignment Solution Exercise: Vector Math Operations Assignment Solution

Exercise: Scripts

Assignment

Make a helloWorld script, such that

When run, the script should display the following text

Hello World!

I am going to learn MATLAB!

Hint: use the command disp to display strings. Check the command help for options and examples.
Hint 2: The simplest way to write a string is to surround text with single quotes, like

'This is a string'

Open the editor, create a new script, write the code and save the script as helloWorld.m

Solution

% helloWorld.m
% my first hello world program in MATLAB
 
disp('Hello World!');
disp('I am going to learn MATLAB!');
 

Exercise: Scalars and Math Operations

Assignment

Consider the variable

where the time constant τ is

Calculate the number of seconds in days and name this variable tau.
Evaluate when

Create a script, write the code and save the script as expRateEval1SCRIPT.m

Solution

% solution of Exercise: Scalars and Math Operations
% script expRateEval1SCRIPT.m
 
Tau_days = 1.5;
 
secPerDay = 60*60*24;
tau = Tau_days * secPerDay;
 
% inefficient solution
t1 = 0;
y1 = (1-exp(-t1/tau));
 
t2 = 1/10;
y2 = (1-exp(-t2/tau));
 
t3 = 120;
y3 = (1-exp(-t3/tau));
 
t4 = 2400;
y4 = (1-exp(-t4/tau));
 
 

Exercise: Math and Vector Operations

Assignment

Consider the variable

where the time constant τ is

Calculate the number of seconds in days and name this variable tau.
Create a row-vector for the time instants

Evaluate when the time t assumes values in the previously defined array.
Create a script, write the code and save the script as expRateEval_2_SCRIPT.m

Solution

% solution of Exercise: Math and Vector Operations
% script: expRateEval_2_SCRIPT.m
 
Tau_days = 1.5;
 
secPerDay = 60*60*24;
tau = Tau_days * secPerDay;
 
% let's define the time row array
t = [ 0, 1/10, 120, 2400];
 
% evaluate the function using the time row-vector
y_vals = (1-exp(-t/tau));
 
 

Exercise: Vectors and Matrices

Assignment

Create the row-vectors

Create the column-vector

By concatenating vectors or matrices according to the following pictures, create the new matrices D, E and F

Save the vectors and the matrices to a file named ExConcatenateMatrices.mat
Hint: use the command save
Create a script, write the code and save the script as exConcatenateVectors_SCRIPT.m

Solution

% exConcatenateVectors_SCRIPT.m
 
a = [1 2];
b = [3 4];
 
c = [ 5; ...
      6 ];
 
D = [ a ; ...
      b  ]
 
E = [D c ]
% equivalent expression:
% E_equiv = [ [ a ; b] c]
 
F = [ [E E]; [a b a]]
% equivalent expression ? 
 
save ExConcatenateMatrices a b c D E F 
% refer to the save command documentation

Exercise: Vector Math Operations

Assignment

Consider the variable

where the time constant τ is

Create a row-vector tVec that has 10000 samples between 0 and 648000 seconds.
Hint: use the command linspace. Do you know any alternative to this command?
Evaluate for each of the time instant t in tVec.
Create a script, write the code and save the script as expRateEval_3_SCRIPT.m

Solution

% solution of Exercise: Vector Math Operations
% script: expRateEval_3_SCRIPT.m
 
clear % clean the MATLAB workspace
Tau_days = 1.5;
 
secPerDay = 60*60*24;
tau = Tau_days * secPerDay;
 
% let's define the time row array tVec
startT = 0;
endT = 648000; 
Nsamples = 10000;
 
tVec = linspace(startT, endT, Nsamples);
 
% evaluate the function using the time row-vector
y_vals = (1-exp(-tVec/tau));
 