From: Wolfgang Bangerth Date: Thu, 17 Mar 2005 14:40:30 +0000 (+0000) Subject: Add a paragraph about complex-valued problems. X-Git-Tag: v8.0.0~14354 X-Git-Url: https://gitweb.dealii.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=d6ef497664b00af7babefbed986f0aa0c0d79eef;p=dealii.git Add a paragraph about complex-valued problems. git-svn-id: https://svn.dealii.org/trunk@10182 0785d39b-7218-0410-832d-ea1e28bc413d --- diff --git a/deal.II/doc/faq.html b/deal.II/doc/faq.html index 4b409d7e5f..f9d7902b6c 100644 --- a/deal.II/doc/faq.html +++ b/deal.II/doc/faq.html @@ -43,6 +43,7 @@ deal.II?
  • 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 @@ -397,6 +398,27 @@

    +
    +

    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 + recommendation: consider such problems as systems of partial + differential equations, where the individual components of the + solution are the real and imaginary part of your unknown. The reason + for this is that for complex-valued problems, the product + <u,v> of two vectors is not the same as + <v,u>, and it is very easy to get this wrong in many + places. If you want to avoid these common traps, then the easiest + way around is to split up you equation into two equations of real + and imaginary part first, and then treat the resulting system as a + system of real variables. This also makes the type of linear system + clearer that you get after discretization, and tells you something + about which solver may be adequate for it. +

    + +

    There is no tutorial program for time-dependent problems!