MATLAB: Identify polygons enclosing a point in a shapefile

polygonshapefile

I have a shapefile containing many polygons that I read in Matlab. Now, I would like to identify which of the polygons in the shapefile interestc/enclose specific points. I have the x and y coordinates of the points. I'm trying to do something like the 'select by location' feature in arcmap.

Best Answer

To get the locations/ points lying inside the polygon use inpolygon.

To get the intersection points use InterX. https://in.mathworks.com/matlabcentral/fileexchange/22441-curve-intersections

To get the nearest points close to a given point use knnsearch.

Also refer this link: https://in.mathworks.com/matlabcentral/answers/522591-fill-inside-a-polygon-with-a-color

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MATLAB: Area of intersection of two ellipses?

with polybool and polyarea

MATLAB: Find points of intersection circle with line

clc; clear all ;
C = [1.5 1.5] ;   % center of cricle 
r = 1.5 ;         % radius of circle 
% 
x = 0:1:3 ; 
y = 0:1:3 ; 
[X,Y] = meshgrid(x,y) ; 
%
th = linspace(0,2*pi) ; 
xc = C(1)+r*cos(th) ; 
yc = C(2)+r*sin(th) ; 
L1 = [xc;yc] ;
% GEt intersecdtion points 
% along X 
[m,n] = size(X) ; 
for i = 1:m
  L2 = [X(i,:) ; Y(i,:)] ; 
  P{i} = InterX(L1,L2)
end
for i = 1:n
  L2 = [X(:,i) Y(:,i)]' ;
  Q{i} = InterX(L1,L2) ;
end
P = cell2mat([P Q]) ;
plot(xc,yc,'b') ;
hold on
plot(X,Y,'r')
plot(X',Y','r')
plot(P(1,:),P(2,:),'*k')

InterX can be downloaded from here: https://in.mathworks.com/matlabcentral/fileexchange/22441-curve-intersections?focused=5165138&tab=function

Best Answer

Related Solutions

MATLAB: Area of intersection of two ellipses?

MATLAB: Find points of intersection circle with line

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