How to create triangle and animate it?

I'm using this code to start but hasnt worked. patch command is giving error and not sure how to resolve it. Please help.

w0 = 1 ;

w1 = 0.5 ;

N = 5 ;

ww = linspace(w1,w0,N) ;

W = [fliplr(ww) ww] ;

ar=0.866; % Aspect ratio for equilateral triangle

h=ar*W;%height of triangle

for i = 1:length(W)

x=[0 W W/2];%x coordinates of vertices

y=[0 0 h];%y coordinates of vertices

patch(x,y,'white')

set(gca,'Color','k','xticklabel',[],'yticklabel',[])

drawnow

pause(0.1)

end

[Binbin Qi]

the length of x and y are not the same.

[Ron]

How do i fix it? Do I need to write W/2 differently?

[Rik]

Question originally posted by JD recovered from Google cache:

I'm using this code to start but hasnt worked. patch command is giving error and not sure how to resolve it. Please help.

w0 = 1 ;
w1 = 0.5 ;
N = 5 ;
ww = linspace(w1,w0,N) ;
W = [fliplr(ww) ww] ;
ar=0.866; % Aspect ratio for equilateral triangle
h=ar*W;%height of triangle
for i = 1:length(W)
x=[0 W W/2];%x coordinates of vertices
y=[0 0 h];%y coordinates of vertices
patch(x,y,'white')
set(gca,'Color','k','xticklabel',[],'yticklabel',[])
drawnow
pause(0.1)
end

[Rena Berman]

(Answers Dev) Restored edit

Answer 1

[Ameer Hamza]

Try this

w0 = 1 ;
w1 = 0.5 ;
N = 5 ;
ww = linspace(w1,w0,N) ;
W = [fliplr(ww) ww] ;

ar=0.866; % Aspect ratio for equilateral triangle
h=ar*W;%height of triangle

fig = figure();
ax = axes();
set(ax,'Color','k','xticklabel',[],'yticklabel',[])
ax.XLim = [0 1];
ax.YLim = [0 1];
p = patch([0 0 0], [0 0 0], 'w');

for i = 1:length(W)
    
    x = [0 W(i) W(i)/2];%x coordinates of vertices
    y = [0 0 h(i)];%y coordinates of vertices
    
    p.Vertices = [x.' y.'];
    
    drawnow
    pause(0.1)
    
end

[Ron]

Thank you so much! Very helpful!

Also, is it possible to add multiple triangles (say 20) to this, instead of 1.

[Ameer Hamza]

I am glad to be of help!

Try this

w0 = 1 ;
w1 = 0.5 ;
N = 5 ;
ww = linspace(w1,w0,N) ;
W = [fliplr(ww) ww] ;

ar=0.866; % Aspect ratio for equilateral triangle
h=ar*W;%height of triangle

n = 200; % number of triangles
area = 20; % 10x10 square for all the triangles
triangle_locations = area*rand(n, 2); % location of triangles

fig = figure();
ax = axes();
set(ax,'Color','k','xticklabel',[],'yticklabel',[])
ax.XLim = [0 area];
ax.YLim = [0 area];

p = gobjects(1, n);
for i=1:n
    p(i) = patch([0 0 0], [0 0 0], 'w');
end

for i = 1:length(W)
    for k = 1:n
        x = [0 W(i) W(i)/2] + triangle_locations(k, 1);%x coordinates of vertices
        y = [0 0 h(i)] + triangle_locations(k, 2);%y coordinates of vertices

        p(k).Vertices = [x.' y.'];
    end
    pause(0.1)
end