| Author | Message | ||
     Andreas Ferber (madprofessor) New member Username: madprofessor Post Number: 1 Registered: 04-2009 |
Hello Iīm new here. I have some qestions about Flexpde I was not able to solve on my own. First question: If i want to multiply a term with the imaginary unit i * term . Is it right to write the following in the Flexpde editor: Complex(0,1)*term I read the Userīs Guide topic "Complex Variables" so I think that must be right. But I think there is a mistake in the Userīs Guide on the first Page to Complex Variables. When I split the equation in two, one for Cr and one for Ci, I get a +Ci instead of a -Ci in the first line and a -Cr instead of +Ci in th second line. Anyway my problem is that if I run my script I get the message !ERROR : Result is not Skalar! I put my skript down below. I would thank you to correct me if I made any rookie mistakes. As I said I looked thru the whole Userīs guide and asked also Google but didnīt get any answers out of it. So thanks a lot for your efforts. TITLE 'Karttesisch 1D dynamisches Kompressionsverhalten' { the problem identification } COORDINATES cartesian1 { coordinate system, 1D,2D,3D, etc } VARIABLES { system variables } Theta = COMPLEX(Theta_r,Theta_i) { choose your own names } Phi = COMPLEX(Phi_r,Phi_i) ! SELECT { method controls } DEFINITIONS { parameter definitions } h_plus=0.001 gamma=1.4 Pe=10000000 kappa=10000000 Pr=0.71 ! INITIAL VALUES EQUATIONS { PDE's, one for each variable } Theta: Theta + h_plus*( gamma-1 )*dx(Phi) + COMPLEX(0,1)*(gamma/Pe)*dxx(Theta)=0 { one possibility } Phi: (gamma)*(Pe^2)*Phi - (kappa^2/h_plus)*dx(Theta) + (kappa^2 + (4/3)*Complex(0,1)*gamma*(Pr)*(Pe))*dxx(Phi)=0 ! CONSTRAINTS { Integral constraints } BOUNDARIES { The domain definition } REGION 1 { For each material region } START(0) Point Value(Phi_r)=0 Point Value(Theta_r)=0 Point Value(Phi_i)=0 Point Value(Theta_i)=0 { Walk the domain boundary } LINE TO (1) Point Value(Phi_r)=1 Point Value(Theta_r)=0 Point Value(Phi_i)=1 Point Value(Theta_i)=0 ! TIME 0 TO 1 { if time dependent } MONITORS { show progress } PLOTS { save result displays } Elevation(Phi_r )From(0) to(1) END | ||
| Robert G. Nelson (rgnelson) Moderator Username: rgnelson Post Number: 1237 Registered: 06-2003 |
There is a logic error in the symbolic processor treatment of complex expressions. The expression simplifier transforms Complex(a,b)+real into Complex(a+real,b), but ignores the related expression real+complex(a,b). A similar error occurs with subtractions. This causes misleading error diagnostics like the one reported in this post. This error has been corrected, and a repaired Win32 version has been posted at www.pdesolutions.com/buglist6.html This correction will be included in the next version release. |