# How to plot temperature distribution T(X,Y) over a 2D rectangular plate in Matlab?

20 views (last 30 days)
Jin Au on 7 Jun 2017
Hi all,
I recently attempted to code the FEM 2D triangular element method to solve for the temperature at each node of a rectangular plate with given temperature boundary conditions. I successfully assigned the (x,y) coordinates at each node and solved the corresponding temperature at each node. By the way, the temperature is a vector. Now I would like to know how to plot a temperature distribution for the reactangular plate in Matlab. I've attempted to use surfc(x,y,T); however, Matlab returned an error that states "T needs to have more than one row or column." I appreaciate for any help provided.
Jin Au on 7 Jun 2017 I apologize for my unclear description. Here's the diagram of the problem.

Star Strider on 7 Jun 2017
If you have three vectors, ‘x’, ‘y’, and ‘T’, first see if scatter3 will plot your data correctly.
If you want to interpolate it, since you have triangulated data, see if scatteredInterpolant (link) will do what you want.

KSSV on 7 Jun 2017
You said FEM....and triangular elements....so you have used unstructured grid. You should be having (x,y) points in the form of nX2 array and nodal connectivity data (say tri)in the form of nX3 array. So you have evaluated temperature T at each node; this is nX1 array, where n is the number of nodes. You can plot this using: trisurf
trisurf(tri,x,y,T)
doc triplot, trimesh , trisurf .
KSSV on 7 Jun 2017
It is easy,to achieve what you said. You are confused.

Precise Simulation on 7 Aug 2017
You can use the FEATool FEM toolbox and postprocessing function to plot unstructured FEM data on triangulated grids and meshes as described in the linked tutorial post.