matlab - 如何绘制等边彩色三角形？

Question

我想在 MATLAB 中制作一个类似于此图的颜色图：

我已经设法创建了创建顶点所需的所有点 [x,y]，并且我有一个包含每个顶点颜色的地图，所以我可以获得以下内容。

但我不明白如何使轴工作。

到目前为止的代码：

% Equilateral grid 
tcorner = [0.0, 0.5,           1.0;
           0.0, 1.0*sqrt(3)/2, 0.0];
tg = triangle_grid( 1/0.05, tcorner );
tgx = tg(1,:);
tgy = tg(2,:);

% Create triangles
tri = delaunay(tgx,tgy);

% Plot
h = trisurf(tri, tgx, tgy, colorvector);

和网格功能：

function triangle_grid(n, tcorner)
    ng = ( ( n + 1 ) * ( n + 2 ) ) / 2;
    tg = zeros ( 2, ng );

    p = 0;

    for i = 0 : n
        for j = 0 : n - i
            k = n - i - j;
            p = p + 1;
            tg(1:2,p) = ( i * t(1:2,1) + j * t(1:2,2) + k * t(1:2,3) ) / n;
        end
    end
end

Answer 1

主要问题是您无法将轴旋转到正确的位置，因为总是翻转到下侧。因此，您需要创建它们。

方法如下：

% Equilateral grid 
tcorner = [0.0, 0.5, 1.0; % x
           0.0, 1.0*sqrt(3)/2,   0.0]; % y
tg = triangle_grid( 1/0.05, tcorner);
tgx = tg(1,:);
tgy = tg(2,:);

% Create triangles
tri = delaunay(tgx,tgy);
col = rand(size(tgx));
trisurf(tri,tgx,tgy,col)
view(0,90)
colormap('lines')

% setting the axes:
ax = gca;
grid off
ax.YAxis.Visible = 'off';
ticks = (0:20:80).';

% bottom axis:
tickpos = linspace(tcorner(1,1),tcorner(1,3),numel(ticks)+1);
ax.XAxis.FontSize = 14;
ax.XAxis.TickValues = tickpos(1:end-1);
ax.XAxis.TickLabels = ticks;
ax.XAxis.TickLabelRotation = 45;
xlabel('X axis title');

% left & right axis:
ticksxpos = linspace(tcorner(1,1),tcorner(1,3),numel(ticks)*2+1);
ticksypos = linspace(tcorner(2,1),tcorner(2,2),numel(ticks)+1);
text(ticksxpos(numel(ticks)+1:-1:2)-0.03,... % left
    ticksypos(end:-1:2)+0.03,...
    num2str(ticks),'FontSize',14,...
    'VerticalAlignment','bottom',...
    'HorizontalAlignment','left',...
    'Rotation',-45)
text(ticksxpos(end:-1:numel(ticks)+2)+0.05,... % right
    ticksypos(1:end-1)-0.03,...
    num2str(ticks),'FontSize',14,...
    'VerticalAlignment','bottom',...
    'HorizontalAlignment','right')
ax.Parent.Color = 'w';

% titles:
text(tcorner(1,2)/2-0.06,tcorner(2,2)/2+0.06,...
    'Left title','FontSize',14,...
    'HorizontalAlignment','center',...
    'Rotation',45)
text(tcorner(1,2)+tcorner(1,2)/2+0.06,tcorner(2,2)/2+0.06,...
    'Right title','FontSize',14,...
    'HorizontalAlignment','center',...
    'Rotation',-45)

我们得到...