Struktura danych MES

RoG@j 2005
11/14/2005
Przepływ danych
Poziom wysoki
Struktura danych MES
Od danych do wyników
Front End i Kernel
Pre- i Postprocesor
Wymagania implementacji
Dane wejściowe
!
Source Data Structures.
!
!
These bear a close relation to the FE model as
the user defined it.
For example, a table of node coordinates.
Dane obliczeniowe
!
Computational Data Structures.
!
!
!
Wyniki
!
As the name suggests, these are organized with
processing efficiency in mind.
The use of arrays is important for this goal.
Example are sparsely stored coefficient matrices,
and partitioned solution vectors.
Front End kontra Kernel
Result Data Structures.
!
!
These contain computed results again organized
in a format that bears close relation to the FE
model.
Examples are completed node displacement
vectors and element stress tables
Struktura danych MES
1
RoG@j 2005
Front End
!
Front End.
!
!
!
Kernel
!
Pre Pocesor
Post Procesor
!
!
!
!
!
!
Many computational data structures can be
implemented as arrays, but the size is only
known at run time.
!
!
Thus, any conventional programming language
that supports dynamic storage management may
be used.
Source data structures may be best
implemented as lists for maximum flexibility
and to facilitate program evolution, because
for the front end computational efficiency is
not usually a major issue.
Struktura danych MES
This program, or suite of programs, handles the processing
steps that require heavy number crunching.
The kernel can run either on the local computer or on a
remote one.
Here “remote” is used in the sense of logically separated
from the local, and does not necessarily imply physical
distance.
Physically remote processing is presently the rule,
however, in the case of large-scale runs on massively
parallel platforms.
Języki implementacji
!
Dwa wymagania
Computational Kernel, also simply called kernel.
!
This program, or suite of programs, defines the
model by direct input or generation of source
data, prepares inputs and control information for
the computational kernel, and handles
visualization of input data as well as analysis
results.
It runs on a local machine such as a workstation
or personal computer with adequate graphic
facilities.
Dalsze kroki…
!
11/14/2005
The ease of implementation of flexible data
structures depends on the implementation
language.
Generally there is a tradeoff effect between
computational efficiency and human effort,
and it is important to balance the two
requirements.
Two general requirements are…
Nazewnictwo
!
Too short names are not the best idea
!
!
Too long names are not the best idea
!
!
i7, k9 … mean NOTHING
Number_Of_Elements_In_The_Model
Short mnemonics are the best idea!
!
NNode, NElem, …
2