Matlab bar chart plotting issue

I have two sets of data and I am using the Matlab "bar" function to create a bar chart. However, I would like to enhance the plot by adding a trend line. When I tried using the "plot" function, I found that the points did not align with the bars in the bar chart. I'd like to know if, when encountering this issue, creating another corresponding array for the x-values and adjusting it is the only way to align the trend line with the bars, or if the "bar" function has built-in capabilities to directly plot a trend line.

clear all ; clc ; clf

set(gcf,'color','w')

load m_time.mat

%%

y1 = 1 : 1 : 10

y2 = [0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0]

y = [y1 ;y2]

bar(m_time_112 , y )

hold on

plot(m_time_112 , y1,'o-')

plot(m_time_112 , y2,'*-')

I want the effect to be something like this: aligning the x-points of the "plot" function with the bars of the "bar" chart.

Answer 1

[Star Strider]

Recent MATLAB releases can return the (x,y) coordinates of the bar end points.

Using those, the result improves considerably —

% type('bar_q.m')

LD = load('m_time.mat');
m_time_112 = LD.m_time_112;

y1 = 1 : 1 : 10;
y2 = [0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0];
y = [y1 ;y2];

figure
hb = bar(m_time_112 , y    );
xep1 = hb(1).XEndPoints;
yep1 = hb(1).YEndPoints;
xep2 = hb(2).XEndPoints;
yep2 = hb(2).YEndPoints;
hold on
plot(xep1  , yep1,'o-')
plot(xep2  , yep2,'*-')

If you have an earlier MATLAB version, this is still possible, however more complicated.

.

[Dyuman Joshi]

This is the way to go.

However, @Star Strider I believe this feature was implemented quite a long while ago. I have seen release version mentioned on any feature introduced recently to a function, specifically in the documentation of bar - section Specify Axes for Bar Graph. (Though this is speculation on my part, I do not have any concrete evidence of this)

[Star Strider]

@Dyuman Joshi — Thank you! The documentation does not say when that was added, however I believe it was a few releases ago, perhaps R2020b. Prior to that, it was necessary to use the undocumented ‘XOffset’ property for each bar group.

[peter huang]

Thanks a million!

[Dyuman Joshi]

@Star Strider Ah, I see. Thanks for the info!

@peter huang if this answer solved your problem, please consider accepting the answer.

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[Star Strider]

@peter huang — My pleasure!

Answer 2

[Raheel Naveed]

clc; clear; close all;

set(gcf,'color','w')
% load m_time.mat  % Load your data here

y1 = 1 : 10;
y2 = 0.1:0.1:1;
y = [y1 ;y2];

numBars = numel(y1);
numSeries = size(y, 1);
groupWidth = min(0.8, numSeries/(numSeries+1.5));


bar(y', 'BarWidth', groupWidth);
hold on
x = 1:numBars;
for i = 1:size(y, 1)
    % Calculate center of each bar
    xAdjusted = x - groupWidth/2 + (2*i-1) * groupWidth / (2*numSeries);
    p = polyfit(x, y(i,:), 1);
    y_fit = polyval(p, x);
    plot(xAdjusted, y_fit, 'o-', 'LineWidth', 2);
end
hold off

[peter huang]

Thanks a million!