Identify polygons enclosing a point in a shapefile

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.

Answer 1

[KSSV]

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

[Maria Czarina Tierra]

Hi, I appreciate you suggestions. However, inpolygon identifies the points inside the polygon, not the polygon itslef. I have predetermined points and I want to know which of the polygons in the shapefile (there are 1664 polygons) enclose the points. After that I need to extract data on those polygons (also in the shapefile). Can I do it using the inpolygon function? Thanks.

[KSSV]

Attach your data...it should be possible. .

[Maria Czarina Tierra]

Attached is the matfile which includes the data from the shapefile of population of the Philippines (Popshp) and the latitude and longitude of the query points. I need to identify the indices of the polygons when the points are located inside the polygons and be able to extract the population of those polygons (POP80 for example)

[KSSV]

What you expect from this?

[Maria Czarina Tierra]

The points must be connected to each other, representing a track. So the track intersects certain parts of the country. I would like to know which parts (polygons) were intersected by the points/lines. Then I can extract the total population of those polygons.

[KSSV]

load("Sample.mat") ; 
plot(lon,lat,'*r')
hold on
x = [Popshp(:).X]' ;
y = [Popshp(:).Y]' ;
L2 = [lon lat] ; 
% Get the Intersection polygon
P = zeros([],1); 
count = 0 ;
for i = 1:length(Popshp)
  L1 = [[Popshp(i).X]' [Popshp(i).Y]'] ; 
  p = InterX(L1',L2') 
  if ~isempty(p)
    count = count+1 ; 
    P(count) = i ; 
    plot(L1(:,1),L1(:,2),'b')
  end
end

Download InterX from the link given in the answer.

[Maria Czarina Tierra]

This works well, Now I can extract data from the indices of the polygons. Thanks a lot!