I am working on a MATLAB project where I have two sets of data:

1- “No Reflection“: Represents baseline coverage area values.
2- “With Reflection“: Represents coverage area values with an additional reflection effect.

I am plotting these two datasets as a grouped bar chart and I want to highlight the difference caused by the reflection. Specifically, I need the section of each bar corresponding to the difference (reflection effect) to be highlighted in a different color on top of the “No Reflection” bars.

Example:
For instance, if:

• “No Reflection” value for the first bar (QAM = 16) is 120 m².
• “With Reflection” value for the same bar is 160 m².

I want to:

1- Plot a bar representing 120 m² (base value for “No Reflection”).

2- Highlight the difference (160 – 120 = 40 m²) on top of the blue bar in red (highlight for the reflection effect).

I want to apply this on all the bars on the image that is on the right side. Any assistance, please?

This is my code:

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];

% Plot for No Reflection
figure('Position', [100, 100, 800, 600]);
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
xticks(1:length(QAM));
xticklabels(string(QAM));
xlabel('QAM Order, M');
ylabel('Coverage Area (m²)');
title({'Coverage Area Without Reflection', 'm-CAP and DCO-OFDM'});
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');
grid on;

% Plot for With Reflection
figure('Position', [100, 100, 800, 600]);
b2 = bar(data_with_reflection', 'grouped');
for k = 1:length(b2)
    b2(k).FaceColor = 'flat';
    b2(k).CData = repmat(custom_colors(k, :), size(b2(k).CData, 1), 1);
end
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'});
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');
grid on;