[英]MATLAB Update trisurf handle
I'm using a Delaunay triangularization to convert a scatter plot to a surface.我正在使用 Delaunay 三角化将散射 plot 转换为表面。 To animate this plot, I want to update the
trisurf
handle instead of creating a new trisurf
plot to reduce overhead and to increase the plotting speed.要为这个 plot 设置动画,我想更新
trisurf
句柄而不是创建新的trisurf
plot 以减少开销并提高绘图速度。
Basically, in a for loop, I want to update the properties of the trisurf
handle h
to obtain the same plot that calling trisurf
again would yield.基本上,在 for 循环中,我想更新
trisurf
句柄h
的属性,以获得与再次调用trisurf
将产生的相同 plot 。
MWE MWE
x = linspace(0,1,11);
y = x;
[X,Y] = meshgrid(x,y);
mag = hypot(X(:),Y(:)); % exemplary magnitude
T = delaunay(X(:),Y(:));
z = 0
h = trisurf(T, X(:), Y(:), z*ones(size(X(:))), mag, 'FaceColor', 'interp'); view([-90 90]);
for i = 1:10
% Compute new values for X, Y, z, and mag
% -> Update properties of handle h to redraw the trisurf plot instead
% of recalling the last line before the for loop again, e.g.,
% h.FaceVertexCData = ...
% h.Faces = ...
% h.XData = ...
end
You can change a few properties of the Patch object returned by trisurf()
:您可以更改
trisurf()
返回的补丁 object 的一些属性:
for i = 1:9
% Compute new values for X, Y, z, and mag
% As an example:
x = linspace(0,1,11-i);
y = x;
[X,Y] = meshgrid(x,y);
mag = hypot(X(:),Y(:));
T = delaunay(X(:),Y(:));
z = i;
Z = z*ones(size(X)); %we could have just called `meshgrid()` with 3 arguments instead
% End recomputation
% Update trisurf() patch: option 1
set( h, 'Faces',T, 'XData',X(T).', 'YData',Y(T).', 'ZData',Z(T).', 'CData',mag(T).' );
pause(0.25); %just so we can see the result
% Update trisurf() patch: option 2
set( h, 'Faces',T, 'Vertices',[X(:) Y(:) Z(:)], 'FaceVertexCData',mag(:) );
pause(0.25); %just so we can see the result
end
where z
is assumed to always be a scalar, just like in the original call to trisurf()
.其中
z
假定始终是一个标量,就像对trisurf()
的原始调用一样。
set()
calls using Vertices
can be some 20% faster than set()
calls using XData
and related properties, and that these strategies are about an order of magnitude faster than multiple trisurf()
calls. Vertices
的多个set()
调用可以比使用XData
和相关属性的set()
调用快大约 20%,并且这些策略比多个trisurf()
调用快大约一个数量级。 When the number of x/y-positions is allowed to vary from 2 to 200, however, run times are about the same for the three approaches.Nruns=1e3;
Nxy_max=20;
for i=1:Nruns
if i==round(Nruns/10)
tic(); %discard first 10% of iterations
end
x = linspace(0,1,randi(Nxy_max-1)+1); %randi([2,Nxy_max]) can be a bit slower
[X,Y,Z] = meshgrid(x,x,randn());
mag = hypot(X(:),Y(:));
T = delaunay(X(:),Y(:));
trisurf(T, X(:), Y(:), Z(:), mag, 'FaceColor', 'interp');
view([-90 90]);
end
tmean_trisurf=1e3*toc()/(Nruns-round(Nruns/10)+1), %in [ms]
h=trisurf(T, X(:), Y(:), Z(:), mag, 'FaceColor', 'interp');
view([-90 90]);
for i=1:Nruns
if i==round(Nruns/10)
tic();
end
x = linspace(0,1,randi(Nxy_max-1)+1);
[X,Y,Z] = meshgrid(x,x,randn());
mag = hypot(X(:),Y(:));
T = delaunay(X(:),Y(:));
set( h, 'Faces',T, 'XData',X(T).', 'YData',Y(T).', 'ZData',Z(T).', 'CData',mag(T).' );
end
tmean_xyzdata=1e3*toc()/(Nruns-round(Nruns/10)+1), %in [ms]
for i=1:Nruns
if i==round(Nruns/10)
tic();
end
x = linspace(0,1,randi(Nxy_max-1)+1);
[X,Y,Z] = meshgrid(x,x,randn());
mag = hypot(X(:),Y(:));
T = delaunay(X(:),Y(:));
set( h, 'Faces',T, 'Vertices',[X(:) Y(:) Z(:)], 'FaceVertexCData',mag(:) );
end
tmean_vertices=1e3*toc()/(Nruns-round(Nruns/10)+1), %in [ms]
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