Heatmap relates with statistics, but heatlines are lines from cold temp to hot temp drawn from heat function...

Dear Kaid Noureddine ,

I suppose that you have the formula of the heatlines, it is a function of temperature, correct?

Now, in the Physics of COMSOL, you should add the suitable Partial Differential Equation (PDE) from "Mathematics". Here, you should select the Temperature as a variable and impose the suitable Boundary conditions to calculate the heatlines.

Best Regards,

Not exactly what you mean dear Muneer Ismael ...

Suppose I have a 2D surface plot of isotherms, and I want to plot heatlines that are normal to the isotherm...exactly in expression (edit), like for example :

-d(T,x)+d(T,y) or something like that...

Please see Equ. (14) in the attached paper. It is Poisson equation (Del^2(H))=d(uT)/dy - d(vT)/dx, where H is the heatline and d(uT)/dy - d(vT)/dx is the source of Poisson equation. Besides to your original Physics (say Heat transfer and laminar flow), you should add a PDE as shown in the Video.

Note: In the added PDE, U2 represents H (heatline)

Hi Muneer Ismael.... Tweaking with what you told me I have nearly found the solution of plotting heatline...

follow the link : https://www.comsol.com/forum/thread/228011/about-heatline

Best regards...