在 MATLAB 条形图中为特定条形颜色添加其他图例

Question

我有以下 MATLAB 代码，它可视化了 DCO-OFDM 和 m-CAP 在覆盖范围与 QAM 阶数方面的差异。条形代表各种配置下的覆盖区域，部分条形部分为红色和蓝色，表示特定效果（例如，LOS+NLOS）。

当前图例已经描述了配置（例如，m-CAP 和 DCO-OFDM 的角度）。但是，我想专门为红色和蓝色条段添加两个额外的图例条目来解释它们的重要性，如附图所示。

目标是在现有图例下添加两个额外的图例，代表：

• 红色条：LOS+NLOS 对 m-CAP 的影响。
• 蓝色条：LOS+NLOS 对 DCO-OFDM 的影响。

这是阐明所需图例布局的图像：

我可以得到帮助来实现这一目标吗？具体来说：

• 如何在不破坏现有图例的情况下为这些条形颜色添加红色和蓝色图例？
• 有没有更有效的方法来达到这个结果？ 预先感谢您的帮助！

这是我用于创建条形图的 MATLAB 代码示例：

close all;
clear variables;
clc;

QAM = [16, 32, 64, 128, 256, 512, 1024];

%% m_CAP modulation

% Beamsteering without reflection
VEC_Beam_no_reflection_mCAP = [
    117.5491   75.1933   53.5396   38.3105   23.0815   13.5634    6.9007; % Theta = 10
    118.2629   76.1452   54.0155   39.0244   23.0815   13.5634    6.9007; % Theta = 30
    118.2629   76.3831   54.0155   39.5003   22.8435   13.5634    6.9007; % Theta = 45
    118.2629   76.6211   54.2534   39.5003   22.8435   13.5634    6.9007  % Theta = 60
];

% Beamsteering with reflection
VEC_Beam_reflection_mCAP = [
    121.3563   77.0970   54.7293   39.7383   22.8435   13.5634    6.9007; % Theta = 10
    141.1065   88.7567   61.6300   42.5937   24.2713   14.5152    7.8525; % Theta = 30
    153.7180   95.6573   67.8168   45.6871   26.6508   14.5152    8.8043; % Theta = 45
    160.3807  100.6544   69.7204   50.4462   28.7924   16.4188    8.8043  % Theta = 60
];

%% DCO-OFDM modulation

% Beamsteering without reflection
VEC_Beam_no_reflection_OFDM = [
    91.3742   59.7264   42.1178   28.7924   16.4188    8.8043    4.9970; % Theta = 10
    95.4194   58.2986   34.7412   25.9369   16.4188   10.7079    4.9970; % Theta = 30
    89.4706   59.4884   44.4973   24.7472   16.4188    8.8043    4.9970; % Theta = 45
    83.5217   69.4825   40.2142   28.7924   16.4188   10.7079    4.9970  % Theta = 60
];

% Beamsteering with reflection
VEC_Beam_reflection_OFDM = [
    94.7055   61.8679   42.1178   28.7924   16.4188    8.8043    4.9970; % Theta = 10
    113.9798   69.7204   42.1178   28.7924   16.4188   10.7079    4.9970; % Theta = 30
    115.6454   74.9554   55.6811   28.7924   16.4188    9.7561    4.9970; % Theta = 45
    114.4557   88.7567   50.6841   34.5033   21.1779   11.6597    4.9970  % Theta = 60
];

%% Combine Data for Bar Chart
angles = [10, 30, 45, 60];
data_no_reflection = [VEC_Beam_no_reflection_mCAP; VEC_Beam_no_reflection_OFDM];
data_with_reflection = [VEC_Beam_reflection_mCAP; VEC_Beam_reflection_OFDM];

% Generate gradient colors for m-CAP (blue) and DCO-OFDM (green)
mCAP_blue_gradient = [linspace(0.8, 0.1, 4)', linspace(0.9, 0.2, 4)', linspace(1.0, 0.3, 4)']; % Light to dark blue
DCO_green_gradient = [linspace(0.7, 0.1, 4)', linspace(0.9, 0.4, 4)', linspace(0.6, 0.2, 4)']; % Light to dark green

% Combine colors
custom_colors = [mCAP_blue_gradient; DCO_green_gradient];

f = figure('Position', [100, 100, 800, 600]);

% Set "HandleVisibility" to off so these bars don't appear in legend
b2 = bar(data_with_reflection', 'grouped','HandleVisibility','off');
for k = 1:length(b2)
    b2(k).FaceColor = 'flat';
    b2(k).CData = repmat([1,0,0], size(b2(k).CData, 1), 1); % [1,0,0] for red bars
end

% Plot for No Reflection
hold on; % To plot 2nd set of bars on top

b1 = bar(data_no_reflection', 'grouped');
for k = 1:length(b1)
    b1(k).FaceColor = 'flat';
    b1(k).CData = repmat(custom_colors(k, :), size(b1(k).CData, 1), 1);
end

% Adjust axis and grid
grid on;
xticks(1:length(QAM));
xticklabels(string(QAM));
xlabel('QAM Order, M');
ylabel('Coverage Area (m²)');
title({'Coverage Area With Reflection', 'm-CAP and DCO-OFDM'});

% Update the legend
legend(["m-CAP \Phi_{1/2}=10°", "m-CAP \Phi_{1/2}=30°", "m-CAP \Phi_{1/2}=45°", "m-CAP \Phi_{1/2}=60°", ...
        "DCO-OFDM \Phi_{1/2}=10°", "DCO-OFDM \Phi_{1/2}=30°", "DCO-OFDM \Phi_{1/2}=45°", "DCO-OFDM \Phi_{1/2}=60°"], ...
       'Location', 'Best');

Answer 1

您可以使用这些颜色创建 2 组假条，以便它们出现在图例中。因此，请使用以下内容而不是代码中的最后一行：

bar(NaN, NaN, 'r') % fake red bar
bar(NaN, NaN, 'b') % fake blue bar

% Update the legend
legend(["m-CAP \Phi_{1/2}=10°", "m-CAP \Phi_{1/2}=30°", "m-CAP \Phi_{1/2}=45°", "m-CAP \Phi_{1/2}=60°", ...
        "DCO-OFDM \Phi_{1/2}=10°", "DCO-OFDM \Phi_{1/2}=30°", "DCO-OFDM \Phi_{1/2}=45°", "DCO-OFDM \Phi_{1/2}=60°", "Red, \Phi_{1/2}=60°", "Blue, \Phi_{1/2}=60°"], ...
       'Location', 'Best'); %%add legend entries for red and blue