How can I count the occurrences of each element in a vector in MATLAB?

While there is no single function in MATLAB to count occurrences of each element, there are a few ways to count elements in a vector:
1. Logical Indexing:
The following code snippet will give the desired output:
y = zeros(size(x));
for i = 1:length(x)
y(i) = sum(x==x(i));
end
For MATLAB R2016b and later, you can use implicit expansion to further simplify the code:
y = sum(x==x')
2. Binning:
You can use the "hist" and "unique" functions as shown here to do the same:
x = [10 25 4 10 9 4 4]
[a,b]=hist(x,unique(x))
3. Third-Party Tools:
For another workaround, see the following file, 'CountMember.m', that was contributed by a MATLAB user to do the same from a single function:
<http://www.mathworks.com/matlabcentral/fileexchange/loadFile.do?objectId=7738&objectType=file>

Comments

Post a Comment

Popular posts from this blog

What are applications of MATLAB?

An exceedingly effective language for specialized calculation is called MATLAB . It consolidates visual, calculations, and programming in a simple to-utilize condition where issues and arrangements are given in surely understood scientific articulations. Algorithm development Scientific and engineering graphics Modeling, simulation, and prototyping Application development, including Graphical User Interface building Math and computation Data analysis, exploration, and visualization Because of the numerous vector and network calculations and controls of calculations connected in MATLAB , the program can be effectively used to reenact complex frameworks of conditions.
Read more

How can I learn genetic algorithm using MATLAB (to be precise).

The easiest way to start learning Genetic Algorithms using MATLAB is to study the examples included with the (Multiobjective) Genetic Algorithm Solver within the Global Optimization Toolbox. You can then replace any of the fitness, selection, variation, creation or plotting functions with yours to solve your specific problem. Another more involved way to learn Genetic Algorithms using MATLAB is to write your own code from scratch. You do not need any specific toolbox for this. Writing the code for a simple Genetic Algorithm is not difficult if you already know how to program in MATLAB. You might also need to use this approach if the solvers in the Global Optimization toolbox do not fit the workflow for the algorithm you have in mind. If the fitness function you are trying to optimize is CPU bound (as it is for many nontrivial genetic algorithm problems), consider implementing the fitness evaluations in C and have MATLAB call those as MEX functions.
Read more

What are some good dissertation tips?

The first thing  you need to know before writing a dissertation  is that it should be a  completed scientific work  containing scientific novelty and/or have practical significance, justifying the proposed provisions. The thesis  should contain the main sections . The information in the sections  should not be repeated. These simple  tips will help you write an amazing dissertation . Step 1 . Before writing a dissertation, it is  necessary  to clearly articulate for itself its general outline, which is an important preparatory stage. Step 2 . Before writing a dissertation, the author must identify for himself the specific purpose and task of describing the  relevant  studies carried out in the work. Step 3 . It is necessary to define quite precisely the  possibilities of solving the problematic moments  when writing the candidate, which the author will have to face in the future. Step 4.  Plan and write do...
Read more