4.2: Methods to Create Vectors in MATLAB

Example \(\PageIndex{1}\) Methods to create vectors in MATLAB

The following code is aloso in the attached file "Methods_to_create_vectors_in_Matlab.mlx".

%% Methods_to_create_vectors_in_Matlab.mlx
% Vectors can be created in Matlab in the following ways.

%% 1. Write a list of values between square brackets:
A = [ 0, 1, 4, 9, 25] % The commas are optional
B = [-3.1 1.789 2/7, exp(2)] % The values can be integers, decimals, or expressions.

%% 2. Use the colon operator to automatically create a vector of equally spaced values:
C = 1:10 % = [1 2 3 4 5 6 7 8 9 10]
% v = n1:n2 creates a vector from n1 to n2
% with an increment of 1
% An “increment” can define the spacing.
% The increment goes in the middle.
D = 0 : 2 : 10 % [0 2 4 6 8 10]
% The increment can be a fraction or a negative number:
E = 2 : 0.5 : 4 % [2 2.5 3 3.5 4]
F = 5 : -1 : 1 % [5 4 3 2 1]

% Alternate method: Multiply by a scale factor:
% Use the factor that multiplying a vector by a scalar
% multiplies each element of the vector by that factor.
theta = (0:(1/6):1) * pi
% theta = [0 0.5236 1.0472 1.5708 2.0944 2.618 3.1416]

%% 3. Derive a vector from another vector
v1 = 11:15 % [11 12 13 14 15]
% Ceate the squares of each element of v1
v2 = v1.^2 % [121 144 169 196 225]
% This uses the element-wise dot operator .^

%% 4. Concatenate vectors (merge 2 or more vectors into 1 vector)
name1 = 'Angela'
name2 = 'Merkel'
name12 = [name1,name2] % 'AngelaMerkel'
% You can add a space between the names:
name1_2 = [name1,' ',name2] % 'Angela Merkel'

%% 5. Use the zeros() function
G = zeros(1,4) % [0 0 0 0] 1 row, 4 columns
% The format is zeros(nrows, ncolumns)
% This is used to initialize a vector before a for loop

% 6. Use the ones() function
H = ones(1,4) % [1 1 1 1] 1 row, 4 columns
J = 3*ones(1,4) % [3 3 3 3] 1 row, 4 columns
% The format is ones(nrows, ncolumns)

% 7. Use the linspace command
K = linspace(1,10,5) % [1.00 3.25 5.50 7.75 10.00]
% This creates a vector of 5 evenly spaced values between 1 and 10

% 8. Use the logspace command
L = logspace(0,3,7) % 1.0E3*[0.001 0.0032 0.010 0.0316 0.100 0.3162 1.00]
% logspace(X1, X2, N) generates a row vector of N logarithmically
% equally spaced points between 10^X1 and 10^X2.

Solution

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