From: bangerth Date: Thu, 23 Aug 2007 15:05:08 +0000 (+0000) Subject: Re-format and see through FAQ. X-Git-Url: https://gitweb.dealii.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=782932b17b7fc72da5e1a750a01f26d7fa8869d4;p=dealii-svn.git Re-format and see through FAQ. git-svn-id: https://svn.dealii.org/trunk@15027 0785d39b-7218-0410-832d-ea1e28bc413d --- diff --git a/deal.II/doc/faq.html b/deal.II/doc/faq.html index 8f466a9d26..48c8aaa358 100644 --- a/deal.II/doc/faq.html +++ b/deal.II/doc/faq.html @@ -31,6 +31,8 @@ libraries exist
  • Can I use deal.II on a Windows platform? +
  • Can I use deal.II on an + Apple MacIntosh?
  • Does deal.II support parallel computing?
  • I can't build the online documentation under Cygwin! @@ -44,18 +46,18 @@
  • How do I solve problem XXX with deal.II?
  • Can I solve problems over complex numbers? -
  • There is no tutorial program for - time-dependent problems!
  • I want to contribute to the development of deal.II! -

    +
    +
    I tried to install deal.II on system X and it does not work. -

    + +

    Even if people reading this list and especially people managing this list belong to the most able programmers in the universe (and a decent number of @@ -63,10 +65,13 @@ wrong, paste the error message into your email. If appropriate, add lines from the file producing the error.

    +
    + -

    How do I change the compiler?

    +
    How do I change the compiler?
    +

    deal.II can be compiled by a number of compilers without problems (see the section +

    + -

    +
    I cannot link with BLAS or LAPACK even if the libraries exist -

    + +

    This is probably due to the introduction of the new GNU FORTRAN Compiler gfortran. If those libraries were compiled with gfortran and you have the old g77 installed, then @@ -91,11 +99,14 @@ test for BLAS to see if it complains about missing symbols indicating such a thing. If so, install the missing compiler.

    +
    + -

    +
    Can I use deal.II on a Windows platform? -

    + +

    First the good news: yes, you can. Still, this answer needs to be more specific. The configuration program for @@ -128,7 +139,7 @@

    -

    Other Windows compilers

    +
    Other Windows compilers

    As long as a compiler is sufficiently standards conforming, and has a command line interface, it may be used to compile the library. In @@ -143,11 +154,14 @@

    +
    + -

    +
    I can't build the online documentation under Cygwin! -

    + +

    The Perl utility from Cygwin distribution (up to version 5.6.1-2) contains a bug that causes a "permission denied" error with in-place @@ -163,13 +177,16 @@ patch to the source code of the perl utility and recompile.

    +
    + -

    +
    My program compiles and links under Cygwin, but it issues a run-time error saying that libXXX.DLL cannot be found! -

    + +

    With Version 5.1.0, deal.II creates and uses shared libraries (DLLs) under cygwin. These DLLs will be linked to your program @@ -192,11 +209,32 @@

    +
    + -

    +
    + Can I use deal.II on an Apple MacIntosh? +
    + +
    +

    + Yes, at least on the more modern OS X operating systems this works + just fine, as long as the developer tools like the GCC compiler, + PERL, etc are installed. The only issue we are currently aware of is + that if deal.II is configured to interface with + PETSc, then PETSc needs to be configured with the + --with-x=0 flag to prevent linking in the X11 libraries + (you probably won't need them anyway). +

    + +
    + + +
    Does deal.II support parallel computing? -

    + +

    Yes. If you use the --with-multithreading --enable-multithreading flags when you run ./configure @@ -234,13 +272,16 @@ METIS, refer to the readme file.

    +
    + -

    Can I use/implement triangles/tetrahedra in - deal.II?

    +
    Can I use/implement triangles/tetrahedra in + deal.II?
    +

    - No, you cannot do either. The basic data structures are too much + No, you can't. The basic data structures are too much tailored to quadrilaterals and hexahedra. Implementing other cells amounts to re-implementing nearly all grid and DoF classes from scratch. On the other hand, the restriction to quadrilaterals and @@ -249,13 +290,19 @@

    +
    + -

    Can I solve problem XXX with deal.II?

    +
    Can I solve problem XXX with deal.II?
    +

    The simple answer is: if it can be written as a PDE, then this is - possible. The more complicated answer is: deal.II + possible as evidenced by the many publications in widely disparate + fields obtained with the help of deal.II. The + more complicated answer is: deal.II is not a problem-solving environment, it is a toolbox that supports you in solving a PDE by the method of finite elements. You will have to implement assembling matrices and right hand side vectors @@ -320,11 +367,14 @@ project added to this page, just contact us.

    +
    + -

    How do I solve problem XXX - with deal.II?

    +
    How do I solve problem XXX + with deal.II?
    +

    There is no general rule on how to attack implementing a program to solve your particular problem. However, the way most often taken is @@ -342,10 +392,13 @@ how to program with deal.II.

    +
    + -

    Can I solve problems over complex numbers?

    +
    Can I solve problems over complex numbers?
    +

    Yes, you can, and it has been done numerous times with deal.II. However, we have a standard @@ -363,51 +416,14 @@ about which solver may be adequate for it.

    - - -

    There is no tutorial program for - time-dependent problems!

    - -

    - While there are a number of projects in which deal.II is used to - write solvers for time-dependent problems, there is indeed no - tutorial program showing this. The reason for this is two-fold: - first, writing tutorial programs takes awfully long, on the order of - at least one full work week, and a time-dependent program would - likely be large and complex so may even take longer. These days, the - main authors of the library unfortunately lack the time for projects - of this size unless it would be directly related to one of their - ongoing projects, and would therefore be a side-product of what they - do anyway. -

    - -

    - The second reason is that over time we have found out that there is - not much common ground in time-dependent solvers: most of our - time-dependent projects build on deal.II serve very different - purposes, from research into error estimators to solving actual - engineering problems. They may change the mesh between each - successive step, once in a while, or never. They may use explicit or - implicit time stepping schemes. Since they differ in so many - aspects, there are only few aspects specific to their - time-dependentness that can be moved to the library, and example - programs would be very different depending on the purpose for which - it was written. Furthermore, unlike most of the other tutorial - programs, it may not serve as a template for your own project unless - it happens to have the same objectives. It may therefore not be - terribly useful to a lot of people. -

    - -

    - That said, if someone has a nice program to contribute as an example - program: we would be delighted to take it in! -

    +
    -

    I want to contribute to the development - of deal.II!

    +
    I want to contribute to the development + of deal.II!
    +

    deal.II is Open Source -- this not only implies that you as everyone else has access to the source codes, it also @@ -478,6 +494,9 @@ interesting to others, there most probably is a way to get it into the library!

    +
    + +