How do I replace elements in a vector with other vectors?

Hi, I am currently trying to replace the elements in a vector called 'seq1' with other vectors. seq1 has 12 numbers ranging from 1 to 9 and I am trying to replace each number with vectors of other numbers as follows:

seq1 = [1 2 3 4 5 6 7 8 9 2 4 5];

rectColor1 = [0.1 0.1 0.1];
rectColor2 = [0.15 0.15 0.15];
rectColor3 = [0.22 0.22 0.22];
rectColor4 = [0.30 0.30 0.30];
rectColor5 = [0.40 0.40 0.40];
rectColor6 = [0.55 0.55 0.55];
rectColor7 = [0.7 0.7 0.7];
rectColor8 = [0.85 0.85 0.85];
rectColor9 = [1 1 1];

for i = 1:numel(seq1)
    if seq1(i) == 1
        seq1(i) = rectColor1;
    elseif seq1(i) == 2
           seq1(i) = rectColor2;  
    elseif seq1(i) == 3
           seq1(i) = rectColor3;
    elseif seq1(i) == 4
           seq1(i) = rectColor4;
    elseif seq1(i) == 5
           seq1(i) = rectColor5;
    elseif seq1(i) == 6
           seq1(i) = rectColor6;
    elseif seq1(i) == 7
           seq1(i) = rectColor7;
    elseif seq1(i) == 8
           seq1(i) = rectColor8;
    elseif seq1(i) == 9
           seq1(i) = rectColor9;
    end
end

However, I keep getting the following error:

Unable to perform assignment because the left and right sides have a different number of elements.

How do I resolve this issue? Thanks in advance.

Answer 1

[Ameer Hamza]

Don't create variable name dynamically like rectColor1, rectColor2, .. It always makes code more difficult. Following shows how you can easily solve the problem using a cell array

seq1 = [1 2 3 4 5 6 7 8 9 2 4 5];

rectColor{1} = [0.1 0.1 0.1];
rectColor{2} = [0.15 0.15 0.15];
rectColor{3} = [0.22 0.22 0.22];
rectColor{4} = [0.30 0.30 0.30];
rectColor{5} = [0.40 0.40 0.40];
rectColor{6} = [0.55 0.55 0.55];
rectColor{7} = [0.7 0.7 0.7];
rectColor{8} = [0.85 0.85 0.85];
rectColor{9} = [1 1 1];

seq1 = cell2mat(rectColor(seq1))

Answer 2

[Image Analyst]

Perhaps this is what you want, where there are 3 rows in the output where each column has the color identified by seq1:

seq1 = [1 2 3 4 5 6 7 8 9 2 4 5]; % 1-by-12
% Define 9 different colors:
rectColor = zeros(3, 9); % Initialize to 3x9 shape.
rectColor(:, 1) = [0.1 0.1 0.1]';
rectColor(:, 2) = [0.15 0.15 0.15]';
rectColor(:, 3) = [0.22 0.22 0.22]';
rectColor(:, 4) = [0.30 0.30 0.30]';
rectColor(:, 5) = [0.40 0.40 0.40]';
rectColor(:, 6) = [0.55 0.55 0.55]';
rectColor(:, 7) = [0.7 0.7 0.7]';
rectColor(:, 8) = [0.85 0.85 0.85]';
rectColor(:, 9) = [1 1 1]';
output = zeros(3, length(seq1)); % Initialize to proper shape, 3-by-12.
% For each column paste in the proper color:
output = rectColor(:, seq1)

You get a 3-by-12 matrix where each column is a color:

output =

Columns 1 through 9

0.1 0.15 0.22 0.3 0.4 0.55 0.7 0.85 1

0.1 0.15 0.22 0.3 0.4 0.55 0.7 0.85 1

0.1 0.15 0.22 0.3 0.4 0.55 0.7 0.85 1

Columns 10 through 12

0.15 0.3 0.4

0.15 0.3 0.4

0.15 0.3 0.4