Change data tip so it shows temperature

I have created a thermal model using matlab pde, and it works well. However, when opening the model in a figure window, the data tip function only shows X, Y, and Z data. I've tried looking for a way to change this so it shows the temperature at certain points (e.g when clicking anywhere on the model, it will show the temperature). Is there anyway I can do this? I feel like this should be intergrated somewhere in the window. Below is my code if needed.

u = symunit;
SIUnits = baseUnits('SI');
gm = multicuboid([2 2.1 2.7 3.2 20],[2.1 2.2 2.7 3.2 20],1.55);
thermalmodel = createpde('thermal','transient');
thermalmodel.Geometry = gm
pdegplot(thermalmodel,'CellLabels','on','FaceAlpha',0.5);
figure('Position',[10,10,800,400]);
subplot(1,2,1)
pdegplot(thermalmodel,'FaceAlpha',0.25,'CellLabel','on')
title('Geometry with Cell Labels')
subplot(1,2,2)
pdegplot(thermalmodel,'FaceAlpha',0.25,'FaceLabel','on')
title('Geometry with Face Labels')
generateMesh(thermalmodel,'Hmax',1);

Water at 30 degrees C

thermalProperties(thermalmodel,'ThermalConductivity',0.616,'SpecificHeat',4184,'MassDensity',997,'Cell',1);

304 stainless steel

thermalProperties(thermalmodel,'ThermalConductivity',16.2,'SpecificHeat',500,'MassDensity',8000,'Cell',2);

Soapstone

thermalProperties(thermalmodel,'ThermalConductivity',6.4,'SpecificHeat',980,'MassDensity',2980,'Cell',3);

Concrete

thermalProperties(thermalmodel,'ThermalConductivity',1.2,'SpecificHeat',880,'MassDensity',2400,'Cell',4);

Soil

thermalProperties(thermalmodel,'ThermalConductivity',6.4,'SpecificHeat',750,'MassDensity',2434,"Cell",5);

thermalmodel.StefanBoltzmannConstant = 5.670373E-8;
thermalBC(thermalmodel,'Temperature',353.15,'Face',[1 2 3 4 5 6]);
thermalIC(thermalmodel,277.65,'Cell',5);
thermalIC(thermalmodel,295.15,'Cell',1);
thermalIC(thermalmodel,293.15,'Cell',[2 3 4]);
thermalBC(thermalmodel,'AmbientTemperature',350.15,"Emissivity",0.38,"Face",[7 8 9 10 11 12]);
thermalBC(thermalmodel,'AmbientTemperature',313.15,'Emissivity',0.94,'Face',[19 20 21 22 23 24]);
thermalBC(thermalmodel,'HeatFlux',-4019.4,'Face',[7 8 9 10 11 12]);
thermalBC(thermalmodel,'HeatFlux',-240.67,'Face',[13 14 15 16 17 18]);
generateMesh(thermalmodel);
tlist = 10:100:86400;

Model after 24 hours (86400 seconds)

thermalresults = solve(thermalmodel,tlist);
T = thermalresults.Temperature;
pdeplot3D(thermalmodel,'ColorMapData',thermalresults.Temperature(:,end));

Answer 1

[Alan Moses]

You can refer to datacursormode documentation which has an example of customizing data tips via a callback function. From my understanding the temperature data is present in the ‘T’ variable. To add customized data tips in the final 3D plot of your script, you can modify the following lines of code by appending this at the end of your script:

dcm = datacursormode;
dcm.UpdateFcn = {@displayCoordinates,T};
function txt = displayCoordinates(~,info,T)
    x = info.Position(1);
    y = info.Position(2);
    z = info.Position(3);
    %temp = T(appropriate indexing);
    txt = ['(' num2str(x) ', ' num2str(y) ', ' num2str(z) ', ' num2str(temp) ')'];
end

Hope this helps!

[Alun Owen]

Thanks for the answer! When adding this code in, the data tip says 'Unable to update data tip using custom update function'. Any idea what I should do here?

[Alan Moses]

Hi Alun, have you updated the 'temp' variable? Uncomment the line where 'temp' is assigned and provide the appropriate indices.

[Alun Owen]

Hi Alan, if you mean change 'temp' variable to 'T' I have done this, but it is still displaying the message. Sorry for not understanding what you mean, I'm quite new to MATLAB.

[Alan Moses]

Hey no problem, when I reproduced this at my side I used 'temp = T(1,1)'. It worked for me, can you share your modified code, so I can take a look at it again.

[Alun Owen]

Hi Alan,

This is what I've done

dcm = datacursormode;
dcm.Enable = 'on';
dcm.UpdateFcn = {@displayCoordinates,temp};

function txt = displayCoordinates(~,info,T)
    x = info.Position(1);
    y = info.Position(2);
    z = info.Position(3);
    temp = T(1,1);
    txt = ['(' num2str(x) ', ' num2str(y) ', ' num2str(z) ', ' num2str(temp) ')'];
end

The data tip function now works, but shows that every temperature is 353.15K - when clicking in the dark blue areas of the model this should be about 280.15K. Any ideas how to fix this?

[Alan Moses]

Yes Alun, you will need to calculate the indexes based on 'x','y','z' values before calculating the 'temp' value.

[Alun Owen]

Ah my bad! I understand now, thanks so much for the help, I really appreicate it.

[Alan Moses]

Glad to help! :)