how to get outline of multiple shapes

Hi,

I have asked about it before

https://www.mathworks.com/matlabcentral/answers/2060069-how-to-get-one-shape-out-of-multiple-shapes?s_tid=srchtitle

but the answer did not fit all my data, so I need help on this one too.

I have multiple shapes I need to merge into a single shape, because I have sets of shapes those I have to merge and compare with each other (put into a one plot). the set of data is attached and I can plot it like this:

plot(X(:, [1:end 1])', Y(:, [1:end 1])')

let me know, if you know how to do it, thanks.

[Image Analyst]

Do you require them to be shape objects or can the answer be a digital image?

[Asliddin Komilov]

I need a shape, x and y axis.

Answer 1

[Asliddin Komilov]

This is the final version:

cutxr=X(1:size(X)/2,:);

cutyr=Y(1:size(Y)/2,:);

cutxl=X(size(cutxr):end,:);

cutyl=Y(size(cutyr):end,:);

% plot(cutxl(:, [1:end 1])', cutyl(:, [1:end 1])'); hold on

% plot(cutxr(:, [1:end 1])', cutyr(:, [1:end 1])')

% find convex hull, use 0 for s

Kr = boundary(double(cutxr(:)),double(cutyr(:)),0);

Kl = boundary(double(cutxl(:)),double(cutyl(:)),0);

Xhr = cutxr(Kr);

Yhr = cutyr(Kr);

Xhl = cutxl(Kl);

Yhl = cutyl(Kl);

% figure

% plot(Xhr,Yhr); hold on

% plot(Xhl,Yhl)

% create shapes to get the whole figure

shapeL=polyshape(Xhl,Yhl, 'simplify', false);

shapeR=polyshape(Xhr,Yhr, 'simplify', false);

shapeRL=[shapeL shapeR];

shape=union(shapeRL);

[xxx, yyy]=boundary(shape);

% figure

% plot(xxx,yyy);

%reshape into same index length to avoid output error

XY=linspace(1, length(xxx),1000);

hullX=interp1(1:1:length(xxx),xxx,XY,'linear');

hullY=interp1(1:1:length(xxx),yyy,XY,'linear');

Answer 2

[Sulaymon Eshkabilov]

Maybe you want to get something like this shape, e.g.:

load('Data.mat')
for ii=1:height(X)
PGON = polyshape(X(ii,:),Y(ii,:),'Simplify',true);
plot(PGON)
hold on
end

Warning: Boundaries with fewer than 3 points were removed.

Warning: Boundaries with fewer than 3 points were removed.

Warning: Boundaries with fewer than 3 points were removed.

Warning: Boundaries with fewer than 3 points were removed.

Warning: Boundaries with fewer than 3 points were removed.

xlim([-3 3])
ylim([0, 0.2])

[Asliddin Komilov]

I need one shape that is from outline of all shapes and for my set of data it will look like a big letter "V".

[Asliddin Komilov]

I think it will work if the 2 halves of the data are treated separately as follows, but I don't know how to join them together and get read of common point.

cutxr=X(1:size(X)/2,:);
cutyr=Y(1:size(Y)/2,:);

cutxl=X(size(X)/2:end,:);
cutyl=Y(size(Y)/2:end,:);
% plot(cutxl(:, [1:end 1])', cutyl(:, [1:end 1])'); hold on
% plot(cutxr(:, [1:end 1])', cutyr(:, [1:end 1])')
% find convex hull
Kr = boundary(double(cutxr(:)),double(cutyr(:)),1);
Kl = boundary(double(cutxl(:)),double(cutyl(:)),1);

Xhr = cutxr(Kr);
Yhr = cutyr(Kr);

Xhl = cutxl(Kl);
Yhl = cutyl(Kl);

% plot the convex hull, show the curve endpoint
plot(Xhr,Yhr); hold on
plot(Xhl,Yhl)