Plotting error bars on grouped bar

R2023b: I am trying to plot error bars on my grouped bar plot. I was able to generate the error bars, however they are offset from the actual bar. I tried two sets of code:

first code:

figure(1); clf; 
hb = bar(y); % get the bar handles
hold on;
for k = 1:size(y,2)
    % get x positions per group
    xpos = hb(k).XData + hb(k).XOffset;
    % draw errorbar
    errorbar(xpos, y(:,k), err(:,k), 'LineStyle', 'none', ... 
        'Color', 'k', 'LineWidth', 1);
end
legend('Boat wake','Wind wave');
set(gca,'xticklabel',{'September Wind'; 'March Boat';'March Wind'; 'May Boat';'May Wind'; 'August Boat'});


second code:
figure(1)
hBar = bar(x,y);                     % Plot Data, Get Handle      
hold on
for k1 = 1:length(hBar)                    % Loop: Plots Error Bars
    hb = get(get(hBar(k1)));
    midbar = mean(hb);
    errorbar(midbar, y(:,k1), errs(:,k1), '.') % plotting errors
    sigbarx(k1,:) = midbar;                % Use To Plot Significance Bars
end

The figure I generated:

Answer 1

[the cyclist]

You need the XEndPonits property of the bars.

% Sample data
data = [1.5, 2.3, 3.2; 2.0, 2.8, 3.5; 1.8, 2.5, 3.0];
errors = [0.2, 0.3, 0.4; 0.3, 0.2, 0.3; 0.2, 0.3, 0.2];

% Number of groups and number of bars in each group
[numGroups, numBars] = size(data);

% Plot the grouped bar chart
figure;
hold on;
hBar = bar(data);

% Get the x positions of the bars
xBar = nan(numGroups, numBars);
for i = 1:numBars
    xBar(:, i) = hBar(i).XEndPoints;
end

% Plot the error bars
for i = 1:numGroups
    for j = 1:numBars
        errorbar(xBar(i, j), data(i, j), errors(i, j), 'k', 'linestyle', 'none', 'CapSize', 10);
    end
end

% Labels and title
xlabel('Group');
ylabel('Value');
title('Grouped Bar Chart with Error Bars');
legend('Bar 1', 'Bar 2', 'Bar 3');
hold off;

[Laura Dunn]

Thank you! Now I cannot get my x labels to show. I used set(gca,'xticklabel',{})

[the cyclist]

Sorry for the delayed reply. I did not get notified of your comment.

I have no issue adding axis labels. Here is the same code above, with labels added. If you cannot get it to work, I suggest opening a new question, and marking this one as resolved, since it solved your original question.

% Sample data
data = [1.5, 2.3, 3.2; 2.0, 2.8, 3.5; 1.8, 2.5, 3.0];
errors = [0.2, 0.3, 0.4; 0.3, 0.2, 0.3; 0.2, 0.3, 0.2];

% Number of groups and number of bars in each group
[numGroups, numBars] = size(data);

% Plot the grouped bar chart
figure;
hold on;
hBar = bar(data);

% Get the x positions of the bars
xBar = nan(numGroups, numBars);
for i = 1:numBars
    xBar(:, i) = hBar(i).XEndPoints;
end

% Plot the error bars
for i = 1:numGroups
    for j = 1:numBars
        errorbar(xBar(i, j), data(i, j), errors(i, j), 'k', 'linestyle', 'none', 'CapSize', 10);
    end
end

% Labels and title
xlabel('Group');
ylabel('Value');
title('Grouped Bar Chart with Error Bars');
legend('Bar 1', 'Bar 2', 'Bar 3');
hold off;

set(gca,"XTick",[1 2 3],"XTickLabel",["yes","no","maybe"])