MATLAB: How to fill the space between these lines

patch

untitled2.png
I have 4 sets of values for the lines
1R = [12 0
12 0.5
12 1
12 1.
12 2
12 2.5
12 3
12 3.5
12 4
12 4.5
12 5
12 5.5
12 6
12 6.5
12 7
12 7.5
12 8
12.5 8
13 8
13.5 8
14 8
14.5 8
15 8
15.5 8
16 8
16.5 8
17 8
17.5 8
18 8
18.5 8
19 8
19.5 8
20 8];
2R = [12 20
12 19.5
12 19
12 18.5
12 18
12 17.5
12 17
12 16.5
12 16
12 15.5
12 15
12 14.
12 14
12 13.5
12 13
12 12.5
12 12
12.5 12
13 12
13.5 12
14 12
14.5 12
15 12
15.5 12
16 12
16.5 12
17 12
17.5 12
18 12
18.5 12
19 12
19.5 12
20 12];
1L =[8 0
8 0.5
8 1
8 1.5
8 2
8 2.5
8 3
8 3.5
8 4
8 4.5
8 5
8 5.5
8 6
8 6.5
8 7
8 7.5
8 8
7.5 8
7 8
6.5 8
6 8
5.5 8
5 8
4.5 8
4 8
3.5 8
3 8
2.5 8
2 8
1.5 8
1 8
0.5 8
0 8];
2L=[8 20
8 19.5
8 19
8 18.5
8 18
8 17.5
8 17
8 16.5
8 16
8 15.5
8 15
8 14.5
8 14
8 13.5
8 13
8 12.5
8 12
7.5 12
7 12
6.5 12
6 12
5.5 12
5 12
4.5 12
4 12
3.5 12
3 12
2.5 12
2 12
1.5 12
1 12
0.5 12
0 12
I tried with the following code but I am getting a gap in the middle.
plot(1R(:,1),1R(:,2),'k');
plot(1L(:,1),1L(:,2),'k');
plot(2L(:,1),2L(:,2),'k');
plot(2R(:,1),L(:,2),'k');
patch([1L(:,1); flipud(1R(:,1))], [1L(:,2); flipud(1R(:,2))], [0.6 0.6 0.6]);
patch([1R(:,1); flipud(2R(:,1))], [1R(:,2); flipud(2R(:,2))], [0.6 0.6 0.6]);
patch([1L(:,1); flipud(2L(:,1))], [1L(:,2); flipud(2L(:,2))], [0.6 0.6 0.6]);
patch([2L(:,1); flipud(2R(:,1))], [2L(:,2); flipud(2R(:,2))], [0.6 0.6 0.6]);
How solve this? any help appreciated.

Best Answer

The easiest way is to define two overlapping rectangles: 
figure
hold all
patch([L1(end,1); R1(end,1); flipud([L1(end,1); R1(end,1)])], [L2(1,1); R1(end,2); flipud([L2(end,2); R2(end,2)])],  [0.6 0.6 0.6], 'EdgeColor',[0.6 0.6 0.6])
patch([L2(1,1); R2(end,2); flipud([L2(1,1); R2(end,2)])], [L2(end,1); L2(end,1); R2(1,2); R2(1,2)], [0.6 0.6 0.6], 'EdgeColor',[0.6 0.6 0.6])
plot(R1(:,1),R1(:,2),'k');
plot(L1(:,1),L1(:,2),'k');
plot(L2(:,1),L2(:,2),'k');
plot(R2(:,1),R2(:,2),'k');
hold off
This works here. It is likely not robust to other matrices.
Another option would be to use the min and max functions to get the limits of the rectangles. That would likely be more robust.
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