3d BAR GRAPH WITH ERROR

Hi,

I am trying to plot 3D bar graph with x_true , y_true coordinates and error percentage. I tried stem, meshgrid, bar3 etc, but not able to do so. can anyone assist me to plot the graph?

figure

x_pred = Net_Out(1,:);

y_pred = Net_Out(2,:);

%

x_true = correct_output(:,1);

y_true = correct_output(:,2);

err = sqrt((x_pred - x_true).^2 + (y_pred - y_true).^2);

figure

meshgrid(x_true, y_true, err);

% figure

% percent_er = 100*errorbar((x_pred - x_true),(y_pred - y_true),err);

% figure

% bar3(err)

Answer 1

[Alamanda Ponappa Poovaya]

I understand you want to create 3D plot of the errors vs x_true and y_true.

First of all, based on the code you have provided, the dimensions of x_pred and y_pred do not match those of x_true and y_true.

You can try evaluating x_pred and y_pred as below

x_pred = (Net_Out(1,:))';
y_pred = (Net_Out(2,:))';

For this kind of plot, using stem3 would provide the kind of plot you are expecting

stem3(x_true, y_true, err);

Documentation :

https://www.mathworks.com/help/matlab/ref/stem3.html

[Jaspreet Kaur]

thank you so much for this. Is it possible if you can tell me how to bar graph instead of line ?

[Alamanda Ponappa Poovaya]

Bar3 would not work in this case. However, to get the visual appearance of bars, you can modify stem3

stem3(x_true, y_true, err,'Marker','none', 'LineWidth', 4)

Try different values for LineWidth as needed

[Jaspreet Kaur]

can you guide me how add colormap according to the height of erro bars?

[Alamanda Ponappa Poovaya]

It requires a bit of a workaround, but the answer below does what you are asking for

https://www.mathworks.com/matlabcentral/answers/414559-3d-stem-plot-colored-by-z-value

[Jaspreet Kaur]

Dear @Alamanda Ponappa Poovaya,

I am trying to get surface plot with same data showe earlier. can you help ?

x_pred = (Net_Out(1,:))';

y_pred = (Net_Out(2,:))';

x_true = correct_output(:,1);

y_true = correct_output(:,2);

err = sqrt((x_pred - x_true).^2 + (y_pred - y_true).^2);

figure

stem3(x_true, y_true, err,'Marker','none', 'LineWidth', 1)

xlabel('x'); ylabel('y'); zlabel('err');

surf (x_true, y_true, err)