open TELEMAC-MASCARET The mathematically superior suite of solvers

Hi,

I have two questions concerning Matisse:

1- I have this message trying to create Telemac file: "Elimination des dependances arrieres non-effectuees".
What does it mean?

2- When importing xyz file, it seems that sometimes I lose the number after the comma for the x and the y...does it happen to anyone else?

Yohann

This is an answer to question 1 :

'dependances arrieres' or 'backward dependency' are only looked at on vector machines. There is in Telemac an algorithm to speed-up element by element matrix-vector products, and this algorithm depends on the numbering of elements (it is something like the contrary of band-width optimisation, we don't want to see the same points appearing in elements that have close numbering, like e.g. point 524 in element 32 and element 33. This is currently useless as very few computers have vector processors.

As to question 2, it seems to me that in Matisse you have to prescribe the number of digits that will be considered (because all real numbers are transformed into integers for internal operations).

With best regards,

Jean-Michel Hervouet

Thank you very much for this quick answer,

I think I understood the meaning of backward dependancy but unfortunately, despite the fact that it is useless, it seems that if we do not eliminate it, it does not allow to proceed in the creation of the telemac file.
My mesh is OK as everything else, but those to messages appear:

'Elimination des dependances arrieres non effectuees'
and then 'impossible d'ecrire le fichier Telemac'.

Is there any trick to get rid of it?

Cordially, Yohann

You are not obliged to do the backward dependency algorithm, and the problem of writing the file does not seem to be linked to this. We tried here a case where the algorithm fails (with too few points in the mesh it fails...) we got the message, but we could write the file without problem. So skip the backward dependency algorithm when you are prompted to do so, as it is not useful, but check your writing rights or the size of your directory ?

JMH