在循环中更改绘图线的颜色

Question

我有一个关于在 MATLAB 中更改绘图中线条颜色的问题。我编写了一个代码，我想在其中更改嵌入在多个 for 循环中的绘图中线条的颜色（代码如下所示）。在代码中，当满足“if 循环”条件时，将创建一个新图（带有自己的图）。我希望每个图都有不同颜色的线条（来自其他图），所以我创建了一个变量 =“NewColor”来增加和更改线条颜色。但是，一直出现以下问题：

假设我处于调试模式，并且在 plot 命令处停止。我运行下一步，并用蓝线创建了一个图。我检查 NewColor 的值，发现 NewColor = 0.1。接下来，我使用“运行到光标”命令跳到下一次激活绘图命令时。当我这样做时，我仍然在“i for loop”中，所以 NewColor 没有改变。我检查编辑器发现 NewColor = 0.1。因此，当我运行下一步时，当前绘图上应该会出现一条蓝线。相反，我难以置信地出现了一条橙色线（除了蓝线）。我不明白，因为在调试器的两个步骤中 NewColor = 0.1，并且代码是这样编写的，所以线条的颜色 = [0,NewColor,0]。如果有人能找到我的方式的错误，将不胜感激。谢谢

ThetaPlot = [40,50];   % Put incident angle as input

Count1 = 0;
Count2 = 0;
NewColor = 0;

for m = 1:length(ThetaPlot)
    NewColor = 0.1;
    Title = sprintf('Angle(%d)',ThetaPlot(m));
    figure('name',Title)
    Count1 = 0;
    for i = 1:length(xrange)-1             % X Coordinate of Start Node
        for j = 1:length(yrange)-1         % Y Coordinate of Start Node
            Count1 = Count1+1;
            for k = 2:length(xrange)       % X Coordinate of End Node
                for l = 2:length(yrange)   % Y Coordinate of End Node
                    Count2 = Count2+1;
                    if ReflRayData(Count2,ThetaPlot(m) - ThetaIncident(1) + 1,Count1) == 1
                        x = [xrange(i),xrange(k)];
                        y = [yrange(j),yrange(l)];
                        plot(x,y,['-',[0,NewColor,0],'o']);
                        hold on;
                    end
                end
                Count2 = 0;
            end
        end
    end
    NewColor = NewColor + 0.02;
end

完整代码：

%% Calculating Angles of Reflection

run = 1; % Set run = 1 for calculations

if run == 1
    xrange = [0:1:14.5]';      % Coordinates to try for Panel Geometry (in)
    yrange = [0:1:36]';        % Coordinates to try for Panel Geometry (in)
    ThetaIncident = [-90:1:90]';     % Incident Angle of Ray (measured relative to normal direction with clockwise postive)
    OvenGlassXrange = [14.5:0.1:36.5]; %Range of X coordinates for Oven Glass

ReflRayData = zeros((length(xrange)-1)*(length(yrange)-1),length(ThetaIncident),(length(xrange)-1)*(length(yrange)-1));  % Matrix containing Reflected Ray Data

Count1 = 0;
Count2 = 0;
for i = 1:length(xrange)-1             % X Coordinate of Start Node
    for j = 1:length(yrange)-1         % Y Coordinate of Start Node
        Count1 = Count1+1;
        for k = 2:length(xrange)       % X Coordinate of End Node
            for l = 2:length(yrange)   % Y Coordinate of End Node
                Count2 = Count2+1;
                for m = 1:length(ThetaIncident)
                    xStart = xrange(i);
                    yStart = yrange(j);
                    xEnd = xrange(k);
                    yEnd = yrange(l);

                    m1 = (yEnd - yStart)/(xEnd - xStart);  % Slope between Start and End Nodes
                    b1 = yStart - m1*xStart;

                    m2 = 1/m1;                             % Slope of normal direction

                    b2 = (yEnd - 0.5*(yEnd - yStart)) - m2*(xEnd - 0.5*(xEnd - xStart));

                    ArbXCoor = 1;                          % Arbitary Point X Coordinate on Normal Line
                    ArbYCoor = m2*ArbXCoor+b2;             % Arbitary Point Y Coordinate on Normal Line

                    ThetaReflected = -ThetaIncident(m);       % Reflected Angle

                    ArbXCoorRot = ArbXCoor*cosd(ThetaReflected) - ArbYCoor*sind(ThetaReflected); % Arbitary Point X Coordinate on Reflected Line
                    ArbYCoorRot = ArbYCoor*cosd(ThetaReflected) + ArbXCoor*sind(ThetaReflected); % Arbitary Point Y Coordinate on Reflected Line

                    m3 = (ArbYCoorRot - (yEnd - 0.5*(yEnd - yStart)))/(ArbXCoorRot - (xEnd - 0.5*(xEnd - xStart))); % Slope of Reflected Line
                    b3 = (yEnd - 0.5*(yEnd - yStart)) - m3*(xEnd - 0.5*(xEnd - xStart));

                    ElemLength = sqrt((yEnd - yStart)^2 + (xEnd - xStart)^2);

                    if min(OvenGlassXrange) < -b3/m3 && -b3/m3 < max(OvenGlassXrange) && -1 < m1 && m1 < 0 && m1 ~= -Inf && m1 ~= Inf && ElemLength < 3
                        ReflRayData(Count2,m,Count1) = 1;
                    end 
                end
            end
        end
        Count2 = 0;
    end
end

%% Plotting

ThetaPlot = [40,50];   % Put incident angle as input

Count1 = 0;
Count2 = 0;
NewColor = 0;

for m = 1:length(ThetaPlot)
    NewColor = 0.1;
    Title = sprintf('Angle(%d)',ThetaPlot(m));
    figure('name',Title)
    Count1 = 0;
    for i = 1:length(xrange)-1             % X Coordinate of Start Node
        for j = 1:length(yrange)-1         % Y Coordinate of Start Node
            Count1 = Count1+1;
            for k = 2:length(xrange)       % X Coordinate of End Node
                hold on;
                for l = 2:length(yrange)   % Y Coordinate of End Node
                    Count2 = Count2+1;
                    if ReflRayData(Count2,ThetaPlot(m) - ThetaIncident(1) + 1,Count1) == 1
                        x = [xrange(i),xrange(k)];
                        y = [yrange(j),yrange(l)];
                        plot(x,y,['-',[0,NewColor,0],'o']);
                        hold on;
                    end
                end
                Count2 = 0;
            end
        end
    end
    NewColor = NewColor + 0.02;
end

Answer 1

代替plot(x,y,['-',[0,NewColor,0],'o']);试试：

plot(x,y,'linestyle','-','marker','o','color',[0,NewColor,0])

Answer 2

根据 Matlab 文档，通过调用 hold on Matlab 使用下一种颜色。

hold on 保留当前坐标区中的图，以便添加到坐标区的新图不会删除现有图。新绘图使用基于轴的 ColorOrder 和 LineStyleOrder 属性的下一个颜色和线型。

因此，在您的代码中，当您在 for 内调用 hold on 时，它只使用下一种颜色。

我的解决方案是将figure; hold on; 放在for 循环之前并在循环中删除那个