# Can I just run some (loopless) code n times without having to modify the code to include a for loop?

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I would like to know if it is possible to run the attached code n times, without having to modify the code (i.e., to include a for loop); yet, every time the code is run, I need the input value (pt) to increment from 1 to n. I also need to store the output variables of the code within in a single variable that contains the output from all n iterations (please see attached code):

close all;

clearvars;

load('F_points.mat');

load('fpep.mat');

xy = F_points';

pt = 299; % choose a point in xy and we'll find the n nearest neighbors.

% Euclidean distance between xy(p,:) and all other points

dist = sqrt((xy(:,1)-xy(pt,1)).^2 + (xy(:,2)-xy(pt,2)).^2);

n = 3; % Find the n closest values (excluding the point selected)

[~, ascendIdx] = sort(dist);

ascendIdx(ascendIdx==pt) = []; %remove the pt point

xyNearest = xy(ascendIdx(1:n),:);

% dist_a = sqrt((fpep(pt,1)-fpep(pt,7)).^2 + (fpep(pt,2)-fpep(pt,8)).^2);

% dist_b = sqrt((fpep(pt,3)-fpep(pt,7)).^2 + (fpep(pt,4)-fpep(pt,8)).^2);

% dist_c = sqrt((fpep(pt,5)-fpep(pt,7)).^2 + (fpep(pt,6)-fpep(pt,8)).^2);

adirector_x = ([fpep(pt,1) - fpep(pt,7)]);

adirector_y = ([fpep(pt,2) - fpep(pt,8)]);

bdirector_x = ([fpep(pt,3) - fpep(pt,7)]);

bdirector_y = ([fpep(pt,4) - fpep(pt,8)]);

cdirector_x = ([fpep(pt,5) - fpep(pt,7)]);

cdirector_y = ([fpep(pt,6) - fpep(pt,8)]);

vector_a = [adirector_x adirector_y];

vector_b = [bdirector_x bdirector_y];

vector_c = [cdirector_x cdirector_y];

chordx = ([xyNearest(:,1) - xy(pt,1)]);

chordy = ([xyNearest(:,2) - xy(pt,2)]);

chordxy = [chordx chordy];

% chord_dist = sqrt((chordx).^2 + (chordy).^2);

% adirector_dist = sqrt((adirector_x).^2 + (adirector_y).^2);

% bdirector_dist = sqrt((bdirector_x).^2 + (bdirector_y).^2);

% cdirector_dist = sqrt((cdirector_x).^2 + (cdirector_y).^2);

for j = 1 : n

CosTheta_a(j) = dot(vector_a,chordxy(j,:))/(norm(vector_a)*norm(chordxy(j,:)));

CosTheta_b(j) = dot(vector_b,chordxy(j,:))/(norm(vector_b)*norm(chordxy(j,:)));

CosTheta_c(j) = dot(vector_c,chordxy(j,:))/(norm(vector_c)*norm(chordxy(j,:)));

end

ThetaInDegrees_a = acosd(CosTheta_a);

ThetaInDegrees_b = acosd(CosTheta_b);

ThetaInDegrees_c = acosd(CosTheta_c);

% Plot

figure()

for ii = 1 : length(chordx)

xvals = [xy(pt,2),xy(pt,2)+chordy(ii)];

yvals = [xy(pt,1),xy(pt,1)+chordx(ii)];

plot(xvals,yvals,'r-')

hold on

end

plot(xy(:,2),xy(:,1),'b.')

hold on

% Show the selected point

plot(xy(pt,2),xy(pt,1),'b.','MarkerFaceColor', 'y')

% Show nearest 'n' dots

plot(xyNearest(:,2),xyNearest(:,1),'ro')

plot(fpep(:,2),fpep(:,1),'k.')

plot(fpep(:,4),fpep(:,3),'k.')

plot(fpep(:,6),fpep(:,5),'k.')

axis equal

Thanks in advance for your help!

##### 3 Comments

Daniel M
on 24 Oct 2019

### Answers (1)

Steven Lord
on 24 Oct 2019

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