open TELEMAC-MASCARET The mathematically superior suite of solvers

Hello everyone,

I am a little bit confused about Mesh%X and Mesh%XEL. I know Mesh%X is the coordinate of points in the mesh which is read in the serafin file for example the slf file created from bluekenue. and I also understand that the Mesh%XEL is the coordiantes of the three points in one element if triangle ( we have XEL1,XEL2,XEL3).

When I looked at subroutine (SUBROUTINE PTEL11) I dont find any difference between Mesh%X and Mesh%XEL.

Can anyone show me graphically the Mesh%X and MESH%XEL for a traingle mesh?

Is the Mesh%X from origion?

My question is related to the surface area calculation in inbief subroutine.

If in inbief considered isoparametric coordinates, means for traingle (0,0),(1,0),(0,1), so where converted the global x coordinate into the local one?
Thanks,

AMANJ

Hello Amanj

Mesh%X (alias X) as you said is the x coordinates of nodes which are read from the geometry file.
Mesh%XEL (respectively YEL) is a vector that gives the x coordinates per element.
So at the end, these two structures contain the same data, but the data are organized differently.
For example, for P1 element (discretization 11 ), X%R is a vector with dimension (NPOIN), this means that for a node I, its x coordinate is given by X%R(I).
whereas XEL is a structure with dimension (NELEM,3). This means that for any element E, its nodes have their x coordinates given by XEL(E,1),XEL(E,2)and XEL(E,3)

In subroutine PTEL11, the only difference is on the organization (and the size) of X and XEL.

To compute the surface of elements, XEL and YEL are used directly (see subroutine sur11.1). The comments in the header of subroutine geoelt is somehow misleading, the computation of area is not done for isoparametric element.

I hope that this helps

with my best regards

Riadh ATA

Thank you so much dear Riadh ATA,

Now its clear.

Cheers,

AMANj