How to get the intersection points ??

1 view (last 30 days)
Eman S
Eman S on 17 Aug 2018
Edited: Eman S on 2 Feb 2020
Hi all, I have the following code to get the intersection points between these multiple lines and these multiple circles.
%%center of circles
X = [0.02 0.44; 0.08 0.58 ;...
0.22 0.57; 0.3 0.9; ...
0.44 0.79; 0.35 0.318;...
0.54 0.29; 0.95 0.11;...
0.93 0.7; 0.82 0.93];
C_M=[X(:,1) X(:,2)];
hold on
%%Assign labels to the points.
Assign_labels_to_all_points ( X ,X(:,1),X(:,2))
hold on
%%Draw circles
theta = linspace(0,2*pi) ;
x = 0.15*cos(theta) ; y =0.15*sin(theta) ;
C_M=[X(:,1),X(:,2)];
deg = 0 : 2.5 : 90;
for i=1:length(deg)
r =2;
x_ax = r*[zeros(size(deg(i))) cosd(deg(i))];
y_ax = r*[zeros(size(deg(i))) sind(deg(i))];
%%plot lines with different angles
plot(x_ax, y_ax, 'LineWidth',1.3)
for index = 1:length(C_M)
if ~isinf(C_M(index))
xx = x+C_M(index,1);
yy = y+C_M(index,2);
%%plot circles
plot(xx,yy,'-b','linewidth',1.5)
for j=1:length(deg)
P = InterX([x+C_M(index,1);y+C_M(index,2)],[r*[zeros(size(deg(j))) cosd(deg(j))];r*
[zeros(size(deg(j))) sind(deg(j))]]);
%%plot intersection points between lines and circles
plot(P(1,:),P(2,:),'or');
end
end
end
end
%%x and y axis limits
xlim([-0.2,1.2])
ylim([-0.2,1.2])
grid on
grid minor
I used the file exchange function InterX. It only draws the intersection points as the following image. But, I can't get these intersection points to store them in matrix or array.
So, my question is: How to get the intersection points between each line and the circles that intersected with that line and store them in array or matrix?? Any suggestions to modify this code??
  1 Comment
Image Analyst
Image Analyst on 1 Feb 2020
Original question (in case he delete this one also):
How to get the intersection points between (each line and the circles that intersected with that line)??
Hi all, I have the following code to get the intersection points between these multiple lines and these multiple circles.
%%center of circles
X = [0.02 0.44; 0.08 0.58 ;...
0.22 0.57; 0.3 0.9; ...
0.44 0.79; 0.35 0.318;...
0.54 0.29; 0.95 0.11;...
0.93 0.7; 0.82 0.93];
C_M=[X(:,1) X(:,2)];
hold on
%%Assign labels to the points.
Assign_labels_to_all_points ( X ,X(:,1),X(:,2))
hold on
%%Draw circles
theta = linspace(0,2*pi) ;
x = 0.15*cos(theta) ; y =0.15*sin(theta) ;
C_M=[X(:,1),X(:,2)];
deg = 0 : 2.5 : 90;
for i=1:length(deg)
r =2;
x_ax = r*[zeros(size(deg(i))) cosd(deg(i))];
y_ax = r*[zeros(size(deg(i))) sind(deg(i))];
%%plot lines with different angles
plot(x_ax, y_ax, 'LineWidth',1.3)
for index = 1:length(C_M)
if ~isinf(C_M(index))
xx = x+C_M(index,1);
yy = y+C_M(index,2);
%%plot circles
plot(xx,yy,'-b','linewidth',1.5)
for j=1:length(deg)
P = InterX([x+C_M(index,1);y+C_M(index,2)],[r*[zeros(size(deg(j))) cosd(deg(j))];r*
[zeros(size(deg(j))) sind(deg(j))]]);
%%plot intersection points between lines and circles
plot(P(1,:),P(2,:),'or');
end
end
end
end
%%x and y axis limits
xlim([-0.2,1.2])
ylim([-0.2,1.2])
grid on
grid minor
I used the file exchange function InterX. It only draws the intersection points as the following image. But, I can't get these intersection points to store them in matrix or array.
So, my question is: How to get the intersection points between each line and the circles that intersected with that line and store them in array or matrix?? Any suggestions to modify this code??

Sign in to comment.

Accepted Answer

Matt J
Matt J on 17 Aug 2018
Edited: Matt J on 17 Aug 2018
Can't you just modify as follows,
P{i,j} = InterX([x+C_M(index,1);y+C_M(index,2)],[r*[zeros(size(deg(j))) cosd(deg(j))];r*
[zeros(size(deg(j))) sind(deg(j))]]);
%%plot intersection points between lines and circles
plot(P{i,j}(1,:),P{i,j}(2,:),'or');
  6 Comments
Matt J
Matt J on 18 Aug 2018
This will give you a map of where the non-empty P{i,j} lie
map=~cellfun('isempty',P)
Eman S
Eman S on 18 Aug 2018
Edited: Eman S on 18 Aug 2018
Thanks so much for your reply and your help.

Sign in to comment.

More Answers (0)

Categories

Find more on Line Plots in Help Center and File Exchange

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!