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FVTool in Octave: the new classdef

The new octave version was recently released and I was excited to test the new classdef, to use my Matlab FVTool with the same functionality in the free (as in free speech and free coffee) Octave. In the process of rewriting the code, I use the design of JFVM.jl. The good news is that now the syntax for JFVM and FVTool are almost identical, except the differences between the languages. The other good news is that now the package supports nonuniform grids. I have already used that feature in a paper (well, an appendix of a paper). The bad news is that the new API is not compatible with the previous version of FVTool. I have updated all the examples to the new API. If you like the older version, please use this link to download it. The main change in the new version is that now CellVariable and FaceVariable are new objects, with a MeshStructure field, and a value, or xvalue, yvalue, and zvalue fields. and therefore you don't need to send MeshStructure as an argument to the discretization and Calculus functions.
One other small change is that I had to disable a function call in the visualization routines, viz. alpha. If you are in Matlab and you like to make your visualization fancier by adding a bit of transparency, consider enabling this function in the visualization routines. The visualization is very basik anyway. I will think about a better way to export the results to other visualization packages for the future versions.
Let's see the code in action:

In [2]:
AGMG 3.x linear solver is NOT available.
warning: PVTtoolbox could not be found; Please run PVTinitialize.m manually
FiniteVolumeToolbox has started successfully.
In [5]:
% create a nonuniform mesh
x=[0,0.1, 0.2, 0.25, 0.4, 0.42, 0.43, 0.6, 0.75, 0.9, 0.91, 0.92, 0.95, 1.0];
m =

<object MeshStructure>

As you can see, m is not of type struct anymore. I have used classdef to define its own object type, in this case MeshStructure.

In [10]:
D=createCellVariable(m, 1.0);
D_face=arithmeticMean(D); # no need to send the mesh variable to the function
<object CellVariable>

You can see that D is now a CellVariable object, and the mesh over which it is defined is stored in:

In [11]:
ans =

<object MeshStructure>

Let's continue and solve a diffusion equation over the 3D domain:

In [13]:
D=createCellVariable(m3, 1.0);
BC.left.a(:)=0; BC.left.b(:)=1.0; BC.left.c(:)=1.0;
BC.right.a(:)=0.0; BC.right.b(:)=1.0; BC.right.c(:)=0.5;
[Mbc, RHSbc]=boundaryCondition(BC);
c=solvePDE(m3, Md+Mbc, RHSbc);

I'll come back with more interesting cases in the FVT blog.


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