MATLAB: How to get all the data points from a 10×10 figure

MATLABpoint

Hi,

I've ploted a 10×10 square. Now i would like to get all the x and y data points in this 10×10 figure. I would like to apply a for loop to get all the points. Can anybody help me ?? Thanks in advance .

Best Answer

[Edit]: You likely already have the points since you just plotted them (as Image Analyst pointed out). However, if you just have the figure and you do not have the code that produced the figure, here's a soltuion below.

You can get the x and y coordinates from your axis like this:

ah = gca;      %handle to axis
XData = [ah.Children.XData]; 
YData = [ah.Children.YData];

XData and YData are vectors.

There's no need for a for-loop. However, if you choose to use one (which is unnecessary),

chil = ah.Children;
XData = cell(size(chil));
YData = cell(size(chil));
for i = 1:length(chil)
    XData{i} = chil(i).XData; 
    YData{i} = chil(i).YData; 
end

which stores (x,y) coordinates for each child in a cell array. You could, of course, orgnaize that differently depending on your needs.

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Try this:

clc;    % Clear the command window.
close all;  % Close all figures (except those of imtool.)
clear;  % Erase all existing variables. Or clearvars if you want.
workspace;  % Make sure the workspace panel is showing.
format long g;
format compact;
fontSize = 20;
x1=0;
x2=10;
y1=0;
y2=10;
wholeHousex = [x1, x2, x2, x1, x1];
wholeHousey = [y1, y1, y2, y2, y1];
plot(wholeHousex, wholeHousey, 'b-', 'LineWidth', 3);
xlabel('Length')
ylabel('Width')
hold on;
text(3,5,'total house W-L')
% Room 1
x1=0;
y1=0;
x2=2;
y2=3;
room1x = [x1, x2, x2, x1,x1];
room1y = [y1, y1, y2, y2,y1];
plot(room1x, room1y, 'r', 'LineWidth', 3);
hold on;
% Room 2
x1=2;
y1=0;
x2=5;
y2=3;
room2x = [x1, x2, x2, x1,x1];
room2y = [y1, y1, y2, y2,y1];
plot(room2x, room2y, 'g', 'LineWidth', 3);
hold on;
% Room 3
x1=5;
y1=0;
x2=10;
y2=3;
room3x = [x1, x2, x2, x1,x1];
room3y = [y1, y1, y2, y2,y1];
plot(room3x, room3y, 'k', 'LineWidth', 3);
hold on;
% Room 4
x1=0;
y1=6;
x2=3;
y2=10;
room4x = [x1, x2, x2, x1, x1];
room4y = [y1, y1, y2, y2, y1];
% Ask the user to click two lines.  You can use improfile() or imdistline() of you have the Image Processing Toolbox.
uiwait(helpdlg('Click on two points.'))
[xUser, yUser] = ginput(2) %this gives me the 2 points
plot(xUser, yUser, 'ro--', 'LineWidth', 2);
% Make flag array to find out if the point is in there.
% One row for every room.  We don't need to check if it's in the entire house since we assume it will be.
inRoom = false(3, 2); % Column 1 for point 1, column 2 for point 2.
% See if points 1 and 2 are in room 1.
if inpolygon(xUser(1), yUser(1), room1x, room1y)
	% The first point is in the whole house

	inRoom(1, 1) = true;
end
if inpolygon(xUser(2), yUser(2), room1x, room1y)
	% The first point is in the whole house
	inRoom(1, 2) = true;
end
% See if points 1 and 2 are in room 2.
if inpolygon(xUser(1), yUser(1), room2x, room2y)
	% The first point is in room 2.
	inRoom(2, 1) = true;
end
if inpolygon(xUser(2), yUser(2), room2x, room2y)
	% The second point is in room 2.
	inRoom(2, 2) = true;
end
% See if points 1 and 2 are in room 3.
if inpolygon(xUser(1), yUser(1), room3x, room3y)
	% The first point is in room 3.
	inRoom(3, 1) = true;
end
if inpolygon(xUser(2), yUser(2), room3x, room3y)
	% The second point is in room 3.
	inRoom(3, 2) = true;
end
% Display results:
inRoom
% Find out if both points are in the same room
roomCount = sum(inRoom, 2)
if any(roomCount == 2)
	% Then both points are in the same room
	message = 'Both points are in the same room';
	uiwait(helpdlg(message));
	return;
end
% Find out where point 1 is by inspecting column 1 for a 1.
point1room = find(inRoom(:, 1))
% Find out where point 2 is by inspecting column 2 for a 1.
point2room = find(inRoom(:, 2))
if isempty(point1room)
	% In whole house but not in any room.  Just say it's room 0.
	point1room = 0;
end
if isempty(point2room)
	% In whole house but not in any room.
	point2room = 0;
end
message = sprintf('Point 1 is in room %d, and Point 2 is in room %d', ...
	point1room, point2room);
uiwait(helpdlg(message));

Best Answer

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