matlab_training:assignments [Tancy Kao]

Powerpoint: matlab_basicvariable01.pptx
Random Function Demo : rand_func_demo.m

Creating Variables

Create a variable called visual_intensity and make it equal to 92. Ensure that the assignment result is not shown on the screen.

visual_intensity = 92; % The semicolon prevents displaying the result after assignment 
% Note that "%" sign indicates a start of a comment

Create a variable called simple_text and assign it value of “A simple text but in Matlab”.

Solution

simple_text = "A simple text but in Matlab";
% Always a good idea to choose clear names for variables. As your code grows larger, those clear names help to remind the logic and context of the code.

Using and Displaying Variables

Create two variables called num_words and num_sentences and assign them values of 6 and 10, respectively. Compute a new variable long_paragraph as a multiple of num_words and num_sentences. Ensure that none of the variable assignments is outputted to the screen.

Solution

num_words = 6;
num_sentences = 10; 
long_paragraph = num_words * num_sentences;

Display values of num_words and num_sentences on the screen.

Solution 1

num_words
num_sentences
% Because no semicolon was placed at the end of variable name, Matlab displays the value of that variable.

Solution 2

disp(num_words);
disp(num_sentences);
% disp is a built-in function and is a short version of the word display. This function is used to show variable values on the screen. 
% When you write a long code, it is a good practice to use disp function to print out results because you can later easily search and find in your code lines where you display final or intermediate results. Of course you will type a bit more, but it will save you time in longer run.

Create two variables called probability_1 and probability_2 and assign them values of 0.1 and 0.01, respectively. Compute a new variable odds by dividing probability_1 by probability_2. Display odds on the screen by ensuring there is semicolon at the end of the line where you display that result.

Solution

probability_1 = 0.1;
probability_2 = 0.01;
odds = probability_1 / probability_2;
disp(odds); 
%

List all the variables that were generated during current session. How many did you get?

Solution

who;
% You will get back list of all variables. There should be if you completed all assignments so far. 
% However, if you completed it your own way, you may get different result. Here is what I got: 
% long_paragraph     num_sentences   num_words         odds              probability_1     
% probability_2     simple_text       visual_intensity

Delete variable probability_1.

Solution

clear probability_1; 
who;
% probability_1 is now missing from the list of in-memory variable. 
% You may notice that function clear
% You will get back list of all variables. There should be if you completed all assignments so far. 
% However, if you completed it your own way, you may get different result. Here is what I got: 
% long_paragraph     num_sentences   num_words         odds              probability_1     
% probability_2     simple_text       visual_intensity

Delete all variable and check that there are none left in the memory.

Solution

clear all
who
% The command will return empty result because we just deleted all variables. 
% You may want to do this to clear up memory, but be careful that you can recompute everything 
% and ensure that you wouldn't lose the results permanently.

Powerpoint: matlab_vectormatrix02.pptx
Vector & Matrix Demo: vector_demo.m
Vector & Matrix Practice:vector_practice.m

Powerpoint:matlab_plotstatement03.pptx
Plot Demo: plot_demo.m
Plot Practice:plot_practice.m

If else, switch, loop Demo: statement_demo.m
If else, switch, loop Practice:statement_practice.m
Practice solution:statement_practice_with_solution.m

Reading and Writing files Demo:read_writefile_demo.m
Reading and Writing files Practice:
- Create a 3 x 6 matrix of random integers, each in the range from 50 to 100. Write this to a file called randfile.mat. Then, read the file just to make sure that it worked!