MATLAB: How to save the final output in a matrix without manually save it on the image panel using patch

imagematrixpatch

I have code like this:

x=[0 10 5];
y=[0 0 8.66];
patch(x,y,'white') 
set(gca,'Color','k','xticklabel',[],'yticklabel',[])
daspect([1 1 1]);
xlim([-5 15])
ylim([-5 15])

How can I save the final output image in a matrix without manually save it on the popup image panel?

I tried to let 'p = patch(x,y,'white')' but it is not the final pop-up output window. Thanks so much!

Best Answer

Use getframe() to get the graphics as an image matrix

x=[0 10 5];
y=[0 0 8.66];
patch(x,y,'white') 
set(gca,'Color','k','xticklabel',[],'yticklabel',[])
daspect([1 1 1]);
xlim([-5 15])
ylim([-5 15])
frame = getframe(gca);
img = frame.cdata;

Related Solutions

MATLAB: Draw filled triangle and possibly change aspect ratio

Hi Chen,

As mentioned by Rik, you can use patch command to draw the triangles and set axes properties to get desired results. Below mentioned code will help you draw triangles with specified aspect ratio:

w=10; %width of triangle
ar=0.866; % Aspect ratio for equilateral triangle
h=ar*w;%height of triangle
x=[0 w w/2];%x coordinates of vertices
y=[0 0 h];%y coordinates of vertices
patch(x,y,'white') %plotting triangle in white color
set(gca,'Color','k','xticklabel',[],'yticklabel',[])%setting background black and removing labels
daspect([1 1 1]);%equal data unit length along x and y axis
xlim([-5 15])
ylim([-5 15])

You can tweak above code to get required geometry for the triangle.

Kindly refer this documentation link to know more details on using ‘patch’ command.

Hope this helps!

MATLAB: How to create randomly distributed triangles

Slightly editing your code gets me to a max framerate of just under 200. Results will vary for different systems.

w = 3 ;
ar=0.866; % Aspect ratio for equilateral triangle
h=ar*w;%height of triangle
p=[];origins=cell(1,10);
figure(1),clf(1)
for k=1:10
    x=[0 w w/2];%x coordinates of vertices
    y=[0 0 h];%y coordinates of vertices
    x=x+15*rand-5;y=y+15*rand-5;%add random
    p(k)= patch(x,y,'white'); %#ok<SAGROW> plotting triangle in white color
    origins{k}=[mean(x) mean(y) 0];%store explicitly to prevent having to retrieve it from an object
end
set(gca,'Color','k','xticklabel',[],'yticklabel',[])%setting background black and removing labels
daspect([1 1 1]);%equal data unit length along x and y axis
xlim([-5 15]),ylim([-5 15])
rotation_per_frame_in_deg=0.8;
target_fps=60;
frametime=1/target_fps;
h_tic=tic;
for n=1:60%do 60 frames
    tic
    for k=1:numel(p)
        rotate(p(k),[0 0 1],rotation_per_frame_in_deg,origins{k})
    end
    drawnow
    pause(frametime-toc)%comment this line to see the max framerate
end
t=toc(h_tic);
fprintf('the fps was %.1f Hz\n',n/t)

Best Answer

Related Solutions

MATLAB: Draw filled triangle and possibly change aspect ratio

MATLAB: How to create randomly distributed triangles

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