Filling area with pattern

82 views (last 30 days)
shane watson
shane watson on 10 Dec 2019
Edited: Adam Danz on 11 Dec 2019
Hello all,
I would like to know the how to fill the area with some pattern [CrossedLines, DiagonalLines, FDiagonalLines, HorizontalLines, Solid, VerticalLines, or XCrossedLines]. I already use this code to fill the area with color:
a=[1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24]
sh2=stairs(1:24,a, '*','color',[0 1 0],'MarkerEdgeColor','r', 'MarkerSize',4,'LineWidth',1.3);
x = [sh2.XData(1),repelem(sh2.XData(2:end),2)]; % Although it works fine for me but I don't what is [XData(2:end),2] means, it would be good if you explain a bit.
y = [repelem(sh2.YData(1:end-1),2),sh2.YData(end)];
viu=fill([x,fliplr(x)],[y,bottom*ones(size(y))],[0 1 0])
viu.FaceAlpha = 0.2;

Accepted Answer

Adam Danz
Adam Danz on 10 Dec 2019
Edited: Adam Danz on 11 Dec 2019
Hi shane, filling with a pattern isn't trivial so I recommend the functions listed in the file exchange. However, here's a fairly easy way to add a polka dot pattern to the area being filled.
The coordinates used to fill form a polygon. This makes an array of random dots that span the size of your polygon and then it removes any dots that are outside of the polygon.
See inline comments for details.
% Here are the coordinates of your polygon used in fill()
polyX = [x,fliplr(x)];
polyY = [y,bottom*ones(size(y))];
viu=fill(polyX,polyY,[0 1 0])
viu.FaceAlpha = 0.2;
% Create array of polkadot coordinates that span the size of the polygon
[dotsX,dotsY] = ndgrid(...
min(polyX): 1 : max(polyX), ...
min(polyY): 1 : max(polyY));
% Determine which coordinates are on or in your polygon
[in,on] = inpolygon(dotsX,dotsY,polyX,polyY);
% extract coordinates in or on polygon
inX = dotsX(in|on);
inY = dotsY(in|on);
% Plot polkadots
hold on
h = plot(inX,inY,'k.','MarkerSize',4,'MarkerFaceColor','k');
See this answer to learn how to avoid the polkadots appearing in the legend.
  4 Comments
shane watson
shane watson on 10 Dec 2019
That's great, lastly, just one thing to share with you. i.e, I use this for another plot belw, but as you can see that polkadots are not appearing between 0 and 1, how to fix that ?and how to increase number of polkadots. I'm sure this the last :) ooo.jpg
Adam Danz
Adam Danz on 11 Dec 2019
In this line from my code below, the middle value determines the interval between dots along the x axis and y axis
[dotsX,dotsY] = ndgrid(...
min(polyX): 1 : max(polyX), ... % for x axis
min(polyY): 1 : max(polyY)); % for y axis
%...............^
You could adjust that number for each axis.
Alternatively you could try something like this below where the last input to linspace() determines the number of dots along the x and y axes.
[dotsX,dotsY] = ndgrid(...
linspace(min(polyX), max(polyX), 10), ... % for x axis
linspace(min(polyY), max(polyY), 10); % for y axis
%.....................................^

Sign in to comment.

More Answers (0)

Categories

Find more on Graphics Object Programming in Help Center and File Exchange

Tags

Community Treasure Hunt

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

Start Hunting!