Chapter 2, Problem 2.2P

To determine

To find:

The output of the following sequence of statements and expressions, and verify them.

mat = [1:3; 44 9 2; 5:-1:3]

mat(3, 2)

mat(2,:)

size(mat)

mat(:, 4) = [8;11;33]

numel(mat)

v = mat(3,:)

v(v(2))

v(1) = []

reshape(mat, 2, 6)

Answer to Problem 2.2P

Solution:

The output of the following sequence of statements and expressions:

“mat = [1:3; 44 9 2; 5:-1:3]”, “mat(3, 2)” “mat(2,:)”, “size(mat)”, “mat(:, 4) = [8;11;33]”, “numel(mat)”, “v = mat(3,:)”, “v(v(2))”, “v(1) = []”, and “reshape(mat, 2, 6)” are “$\text{mat}=\left[\begin{array}{ccc}1& 2& 3\\ 44& 9& 2\\ 5& 4& 3\end{array}\right]$”, “ans = 4”, “ans = 44 9 2”, “ans = 3 3”, “$\text{mat}=\left[\begin{array}{cccc}1& 2& 3& 8\\ 44& 9& 2& 11\\ 5& 4& 3& 33\end{array}\right]$”, “ans = 12”, “5 4 3 33”, “ans = 33”, “v = 4 3 33”, and “$\left[\begin{array}{cccccc}1& 5& 9& 3& 3& 11\\ 44& 2& 4& 2& 8& 33\end{array}\right]$” respectively.

Explanation of Solution

Consider the following statement,

mat = [1:3; 44 9 2; 5:-1:3]

The statement will generates the matrix with the elements of the row with 1, 2, 3; second row 44, 9, 2; and the third row with 5, 4, 3.

So, the output is “$\text{mat}=\left[\begin{array}{ccc}1& 2& 3\\ 44& 9& 2\\ 5& 4& 3\end{array}\right]$”

Consider the following statement,

mat(3, 2)

This command generates the value that is placed at third row and second column of the matrix “mat”.

So, the output is “ans = 4”.

Consider the following statement,

mat(2,:)

This command generates the second row elements of the matrix “mat”.

So, the output is “ans = 44 9 2”.

Consider the following statement,

size(mat)

This command generates the order of matrix.

So, the output is “ans = 3 3”.

Consider the following statement,

mat(:, 4) = [8;11;33]

This command includes the fourth column to the matrix “mat”.

So, the output is “$\text{mat}=\left[\begin{array}{cccc}1& 2& 3& 8\\ 44& 9& 2& 11\\ 5& 4& 3& 33\end{array}\right]$”.

Consider the following statement,

numel(mat)

This command generates the number of elements present in the matrix “mat”.

So, the output is “ans = 12”.

Consider the following statement,

v = mat(3,:)

This command generates the third row elements from the matrix “mat”.

So, the output is “5 4 3 33”.

Consider the following statement,

v(v(2))

Since, $\text{v}\left(2\right)=4$ for the matrix “mat”, the output will be $\text{v}\left(4\right)$ that is 33.

So, the output is “ans = 33”.

Consider the following statement,

v(1) = []

This command generates the elements of “v” eliminating the first elements.

So, the output is “v = 4 3 33”.

And consider the following statement,

reshape(mat, 2, 6)

This command changes the order of the matrix from $3\times 3$ to $2\times 6$.

So, the output is “$\left[\begin{array}{cccccc}1& 5& 9& 3& 3& 11\\ 44& 2& 4& 2& 8& 33\end{array}\right]$”.

MATLAB Code:

clc

clear all

close all

mat = [1:3; 44 9 2; 5:-1:3]

% Define the instruction in which the statement will generates the matrix with the elements of the row with 1, 2, 3; second row 44, 9, 2; and the third row with 5, 4, 3.

mat(3, 2)

% Define the instruction in which the command generates the value that is placed at third row and second column of the matrix “mat”.

mat(2,:)

% Define the instruction in which the command generates the second row elements of the matrix “mat”.

size(mat)

% Define the instruction in which the command generates the order of matrix.

mat(:, 4) = [8;11;33]

% Define the instruction in which the command includes the fourth column to the matrix “mat”.

numel(mat)

% Define the instruction in which the command generates the number of elements present in the matrix “mat”.

v = mat(3,:)

% Define the instruction in which the command generates the third row elements from the matrix “mat”.

v(v(2))

% Define the instruction in which the command generates the value of the v(v(2)).

v(1) = []

% Define the instruction in which the command generates the elements of “v” eliminating the first elements.

reshape(mat, 2, 6)

% Define the instruction in which the command changes the order of the matrix from 3 into 3 to 2 into 6.

Save the MATLAB script with name, chapter2_54793_2_2P.m in the current folder. Execute the script by typing the script name at the command window to find the answer of the given following sequence of statements and expressions.

Result:

Therefore, the output of the following sequence of statements and expressions:

“mat = [1:3; 44 9 2; 5:-1:3]”, “mat(3, 2)” “mat(2,:)”, “size(mat)”, “mat(:, 4) = [8;11;33]”, “numel(mat)”, “v = mat(3,:)”, “v(v(2))”, “v(1) = []”, and “reshape(mat, 2, 6)” are “$\text{mat}=\left[\begin{array}{ccc}1& 2& 3\\ 44& 9& 2\\ 5& 4& 3\end{array}\right]$”, “ans = 4”, “ans = 44 9 2”, “ans = 3 3”, “$\text{mat}=\left[\begin{array}{cccc}1& 2& 3& 8\\ 44& 9& 2& 11\\ 5& 4& 3& 33\end{array}\right]$”, “ans = 12”, “5 4 3 33”, “ans = 33”, “v = 4 3 33”, and “$\left[\begin{array}{cccccc}1& 5& 9& 3& 3& 11\\ 44& 2& 4& 2& 8& 33\end{array}\right]$” respectively.