如何在 MATLAB 中从矩阵序列中绘制动画图

Question

我有使用 Wolff 算法在 MATLAB 中模拟 XY 模型的代码，我想实现一个 pcolor/color map 来根据它们在系统中的角度来演示每个旋转。但我希望它随着角度的变化而变化。

知道怎么做吗？

这是我希望它看起来如何的示例https://i.stack.imgur.com/aSp7s.png

Answer 1

如果将晶格的每个快照保存在元胞数组 A{t} 中，则可以使用以下函数查看并保存为视频（如果 fileName 不为空，则该函数保存一个 mp4 视频）。

另一种选择是调整函数view_lattice 来运行您的模拟（老实说，出于性能问题，我不建议这样做）。我会标记你应该在哪里编辑以进行“实时”模拟

这至少是 MATLAB R2019b（虽然它可能与早期版本兼容，但不能保证）。

文件view_lattice.m

function view_lattice(A,fileName)
% for a 'live' simulation, you will have to remove A from the input 
% parameters and add the ones you need for the XY Wolff algorithm,
% which will be used to calculate each configuration A in the time loop below
% you will also need to remove the assert statements for 'live' simulation
%
% otherwise, you save snapshots from your simulation
% and use this function as is
% 
% A -> A{k}[m,n] snapshot k containing the angles of spins in lattice site at row m and col n
% fileName -> if contains string, then records a video with the snapshots and name it with this string
    assert(iscell(A) && all(cellfun(@(a)isnumeric(a) && ismatrix(a),A)),'A must be cell of numeric matrices');
    assert(ischar(fileName),'fileName must be either an empty char or contain a file name');
    
    recordVideo = ~isempty(fileName);
    
    if recordVideo
        vw = setup_video(fileName);
    else
        vw = [];
    end
    % setting some default axis properties to speed-up plotting
    set(0,'DefaultAxesPlotBoxAspectRatio',[1 1 1],'DefaultAxesDataAspectRatioMode','manual','DefaultAxesDataAspectRatio',[1,1,1],'DefaultAxesNextPlot','replace');
    
    fh = figure;
    ax=axes;
    for t = 1:numel(A) % for 'live' simulation, this loop should be the time loop
        % here you calculate the new configuration A
        % and call the function below with A instead of A{t}
        vw = record_frame(vw,fh,ax,A{t},t,recordVideo);
    end
    
    % any video to close?
    if recordVideo
        vw.close();
    end
end

function vw = record_frame(vw,fh,ax,A,t,recordVideo)
    imagesc(ax,A);
    title(ax,sprintf('snapshot %g',t)); % if you want, y
    axis(ax,'square');
    daspect(ax,[1,1,1]);
    pause(0.01);
    if recordVideo
        vframe = getframe(fh);
        vw.writeVideo(vframe);
    end
end

function vw = setup_video(fileName)
    vid_id = num2str(rand,'%.16g');
    vid_id = vid_id(3:6);
    vid_id = [fileName,'_',vid_id];
    % Initialize video
    vw = VideoWriter([vid_id,'.mp4'], 'MPEG-4'); %open video file
    vw.Quality = 100;
    vw.FrameRate = 16;
    vw.open();
end

测试脚本：test.m

clearvars
close all

A = cell(1,30);

for t = 1:numel(A)
    % creating a sequence of random snapshots only for illustration
    A{t} = rand(20,20);
end

% viewing the animation and saving it as a video with name test
view_lattice(A,'test');

输出