From 8910e38415daf351c7c0bbc35db8358afa63adaa Mon Sep 17 00:00:00 2001 From: wolf Date: Sun, 11 Sep 2005 01:52:02 +0000 Subject: [PATCH] . git-svn-id: https://svn.dealii.org/trunk@11399 0785d39b-7218-0410-832d-ea1e28bc413d --- .../step-19.data/intro.html | 39 ++++++++++++++++++- 1 file changed, 38 insertions(+), 1 deletion(-) diff --git a/deal.II/doc/tutorial/chapter-2.step-by-step/step-19.data/intro.html b/deal.II/doc/tutorial/chapter-2.step-by-step/step-19.data/intro.html index f9707db8ba..d343cd41c5 100644 --- a/deal.II/doc/tutorial/chapter-2.step-by-step/step-19.data/intro.html +++ b/deal.II/doc/tutorial/chapter-2.step-by-step/step-19.data/intro.html @@ -11,4 +11,41 @@ output files into a single one.

-Thus was the beginning of step-19. \ No newline at end of file +Thus was the beginning of step-19: it is the program that reads a number of +files written in intermediate format, and merges and converts them into the +final format that one would like to use for visualization. It can also be used +for the following purpose: if you are unsure at the time of a computation what +graphics program you would like to use, write your results in intermediate +format; it can later be converted, using the present program, to any other +format you may want. +

+ +

+While this in itself was not interesting enough to make a tutorial program, we +have used the opportunity to introduce one class that has proven to be +extremely help- and useful in real application programs, but had not been +covered by any of the previous tutorial programs: the +ParameterHandler class. This class is used in applications that +want to have some of their behavior determined at run time, using input +files. For example, one may want to specify the geometry, or specifics of the +equation to be solved, at run time. Other typical parameters are the number of +nonlinear iterations, the name of output files, or the names of input files +specifying material properties or boundary conditions. +

+ +

+Working with such parameter files is not rocket science. However, it is rather +tedious to write the parsers for such files, in particular if they should be +extensible, be able to group parameters into subsections, perform some error +checks such as that parameters can have only certain kinds of values (for +example, it should only be allowed to have integer values in an input file for +parameters that denote a number of iteration), and similar requirements. The +ParameterHandler class allows for all this: an application program +will declare the parameters it expects (or call a function in the library that +declares a number of parameters for you), the ParameterHandler +class then reads an input file with all these parameters, and the application +program can then get their values back from this class. +

+ +

+what these three steps do... -- 2.39.5