Helmholtz equation

Please choose a case:
u in C4
on [0,1]x[0,1]		 h2 convergence
u in C2 on [0,1]x[0,1]
and C3 on ]0,1[x]0,1[		 Convergence is slower
Userdefined,
Exact solution unknown.		 Please specify the the load function f here as a formula (for example 1+x**2+y**2) following Fortran- conventions: The formula may extend over three lines and may make use of the constants pi, e=exp(1) and sqrt2=sqrt(2), but the variables must be named x and y.
f(x,y) =

Please specify the type of boundary conditions on the four edges:
At least on one edge you must specify Dirichlet data.
Dirichlet on x = a von Neumann on x = a
Dirichlet on x = b von Neumann on x = b
Dirichlet on y = c von Neumann on y = c
Dirichlet on y = d von Neumann on y = d

And here you specify the functions delivering the boundary values, again as formulas following the same rules as for f.
the function for x=a:
phi0(x,y) =
the function for x=b:
phi1(x,y) =
the function for y=c:
psi0(x,y) =
the function for y=d:
psi1(x,y) =

Please specify lambda here:
lambda = Important : lambda <= 0 !
And here the data defining the rectangle [a,b]x[c,d]:
a = b =
c = d =

Please specify the number n of subintervals of [a,b] resp. m of [c,d].
This results in n deltax=(b-a)/n and deltay=(d-c)/m.
n = Important : 3 <= n <= 100 !
m = Important : 3 <= m <= 100 !

For defining a view point we need the rotation angles for the x-axis and the u-axis:
Important: 0 <= xang <= 180, 0 <= uang <= 360 (in degrees)
For xang = 0 the x-axis is horizontal on the screen and hence the y- axis vertical on the screen and for uang=0 the u-axis is vertically to the screen (you see little then clearly)
xang=
uang=

Click on "evaluate", in order to submit your input.

Back to the theory page

 Back to the top!

29.05.2016