Matlab Arrays not populating correctly

Hi all, I'm getting a problem with MATLAB where the values being inserted into a vector are appearing as [] instead of [rand, 0].

This is my code:

M = 10;      %no of chromosomes (candidate solutions)
N = 2;          %no of genes

for k = 1 : M
population.Chromosomes(M).Gene(:) = [rand, 0];
population.Chromosomes(k).fitness = fitnessFunction(population.Chromosomes(M).Gene(:) );
end

The matrix population.Chromosomes should show all the values in the gene column as [0.8344,0] for example, and I'm sure these cells have values as the fitness vector has a value.

Answer 1

[Cris LaPierre]

Your code is telling it to assign [rand,0] to gene(M). This means that it will always assign the value to the 10th row, which is what it looks like it is doing. You are assigning correctly for fitness, and you can see the values of Gene change each time since the values for fitness are different in every row.

Did you mean to use k instead?

M = 10;      %no of chromosomes (candidate solutions)

for k = 1 : M
    population.Chromosomes(k).Gene = [rand, 0];
end

And now to visualize the results.

population.Chromosomes.Gene

ans = 1×2

0.8894 0

ans = 1×2

0.4122 0

ans = 1×2

0.4319 0

ans = 1×2

0.8130 0

ans = 1×2

0.4936 0

ans = 1×2

0.8817 0

ans = 1×2

0.8535 0

ans = 1×2

0.0575 0

ans = 1×2

0.7653 0

●

ans = 1×2

0.5670 0

●

[Cathal White]

Thank you.

Answer 2

[dpb]

You've got a typo...

population.Chromosomes(M).Gene(:) = [rand, 0];

is writing into the location M(=10) every time.

[Cathal White]

Thank you.