How to make a vector in Matlab and Octave
To create a vector with Matlab or Octave type
vettore = [ a1; a2; a3; ... ; an ]
The elements of the vector are enclosed in square brackets.
Each element is separated from the next element in the list by a semicolon.
The result is a column vector.
Note. To create a line vector, separate elements with a comma or a space.
Examples
Example 1 (column vector)
To define this column vector
$$ v = \begin{pmatrix} 5 \\ 7 \\ 1 \\ 0 \\ -1 \end{pmatrix} $$
you have to create an array by separating the elements from each other with the semicolon symbol (;).
>> v = [5;7;1;0;-1]
In this way the elements of the vector are arranged in a single column divided into five different rows.
Example 2 (Row Vector)
To define a row vector
$$ v = \begin{pmatrix} 5 & 7 & 1 & 0 & -1 \end{pmatrix} $$
you have to create an array with the elements separated from each other by a comma (,)
>> v = [5,7,1,0,-1]
The same result is obtained by separating the elements with a space instead of a comma
>> v = [5 7 1 0 -1]
In both cases the vector has the elements arranged in a single row on five different columns.
Example 3
To create a vector of integers between a lower bound to an upper bound
>> v = [1:8]
The result is the vector
v = 1 2 3 4 5 6 7 8
Example 4
To create a vector of integers between a lower bound and an upper bound with a step other than +1, use the syntax [initial value: step: final value]
>> v = [10: -2 :1]
The result is
$$ v = \begin{pmatrix} 1 & 2 & 3 & 4 & 5 & 6 & 7 & 8 \end{pmatrix} $$
Example 5
The step can also be a decimal value.
>> v = [0: .2 :1]
The result is the vector
$$ v = \begin{pmatrix} 0.0 & 0.2 & 0.4 & 0.6 & 0.8 & 0.8 & 1.0 \end{pmatrix} $$
Example 6
To create a vector composed of n elements between a lower bound x1 and an upper bound x2 you can also use the function linspace(x1,x2,n)
>> v=linspace(0,1,5)
The result is the vector
$$ v = ( \ 0.00000 \ , \ 0.25000 \ , \ 0.50000 \ , \ 0.75000 \ , \ 1.00000 \ ) $$
Example 7
To create a null column vector use the function zeros(n,1)
>> zeros(5,1)
The output result is a null column vector
$$ v = \begin{pmatrix} 0 \\ 0 \\ 0 \\ 0 \\ 0 \end{pmatrix} $$
Example 8
To create a null row vector, use the function zeros(1,n)
>> zeros(1,5)
The output result is a null row vector
$$ v = ( \ 0 \ , \ 0 \ , \ 0 \ , \ 0 \ , \ 0 \ ) $$
Example 9
To create a column vector with all elements equal to 1 use the function ones(n,1)
>> ones(5,1)
The output result is a column vector
$$ v = \begin{pmatrix} 1 \\ 1 \\ 1 \\ 1 \\ 1 \end{pmatrix} $$
Example 10
To create a row vector with all elements equal to 1 use the function ones(1,n)
>> ones(1,5)
The output result is a row vector
$$ v = ( \ 1 \ , \ 1 \ , \ 1 \ , \ 1 \ , \ 1 \ ) $$
