# How can I write the first function as a part of the second?

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Answered: Akanksha Shrimal on 27 Apr 2022
I have been given a peculiar task by my instructor. There are two K means code, I need to write a K means function which captures the functionality of both. The first was used for image segmentation and the second to K means cluster data points. I understand the algo in both but I dont understand how to use the X in function 1 by using the 2nd function.
% function 1
function X = my_kmeans(F,K,iter)
CENTS = F( ceil(rand(K,1)*size(F,1)) ,:);
DAL = zeros(size(F,1),K+2);
for n = 1:iter
for i = 1:size(F,1)
for j = 1:K
DAL(i,j) = norm(F(i,:) - CENTS(j,:));
end
[Distance, CN] = min(DAL(i,1:K)); % 1:K are Distance from Cluster Centers 1:K
DAL(i,K+1) = CN; % K+1 is Cluster Label
DAL(i,K+2) = Distance; % K+2 is Minimum Distance
end
for i = 1:K
A = (DAL(:,K+1) == i); % Cluster K Points
CENTS(i,:) = mean(F(A,:)); % New Cluster Centers
if sum(isnan(CENTS(:))) ~= 0 % If CENTS(i,:) Is Nan Then Replace It With Random Point
NC = find(isnan(CENTS(:,1))); % Find Nan Centers
for Ind = 1:size(NC,1)
CENTS(NC(Ind),:) = F(randi(size(F,1)),:);
end
end
end
end
X = zeros(size(F));
for i = 1:K
idx = find(DAL(:,K+1) == i);
X(idx,:) = repmat(CENTS(i,:),size(idx,1),1);
end
end
% Function 2
function [means,Nmeans,membership] = my_kmeans_data(X,K,maxerr)
[Ndata, dims] = size(X);
dist = zeros(1,K);
means = zeros(K,dims);
if (nargout > 2)
membership = zeros(Ndata,1);
end
% Initial prototype assignment (arbitrary)
for i=1:K-1
means(i,:) = X(i,:);
end
means(K,:) = mean(X(K:Ndata,:));
cmp = 1 + maxerr;
while (cmp > maxerr)
% Sums (class) and data counters (Nclass) initialization
class = zeros(K,dims);
Nclass = zeros(K,1);
% Groups each elements to the nearest prototype
for i=1:Ndata
for j=1:K
% Euclidean distance from data to each prototype
dist(j) = norm(X(i,:)-means(j,:))^2;
end
% Find indices of minimum distance
index_min = find(~(dist-min(dist)));
% If there are multiple min distances, decide randomly
index_min = index_min(ceil(length(index_min)*rand));
if (nargout > 2)
membership(i) = index_min;
end
class(index_min,:) = class(index_min,:) + X(i,:);
Nclass(index_min) = Nclass(index_min) + 1;
end
for i=1:K
class(i,:) = class(i,:) / Nclass(i);
end
% Compare results with previous iteration
cmp = 0;
for i=1:K
cmp = norm(class(i,:)-means(i,:));
end
% Prototype update
means = class;
end
Nmeans = Nclass;
end
Note both the codes belong to respecctive owners and I do not own the copyright. I am just using them for academic purpose.

Akanksha Shrimal on 27 Apr 2022
Hi,
Can you clearly explain what exactly you mean by using X in function 1 by using the 2nd function.
What use case are you trying to achieve with this.

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