Attaches a Property to a TwoDimensional Grid
Description
Calculates the value of a given property at the middle of grid cells
(mid
) and at the interfaces of the grid cells (int
).
Two possibilities are available: either specifying a mathematical function
(func
) that describes the spatial dependency of the property, or
asssuming a constant value (value
). To allow for anisotropy, the
spatial dependency can be different in the x and y direction.
For example, in a sediment model, the routine can be used to specify the porosity, the mixing intensity or other parameters over the grid of the reactangular sediment domain.
Usage
1 2 3 4 5 
Arguments
func 
function that describes the spatial dependency in the
xdirection; defined as 
value 
constant value given to the property in the xdirection 
grid 
list specifying the 2D grid characteristics, see

y.func 
function that describes the spatial dependency in the
ydirection; defined as 
y.value 
constant value given to the property in the ydirection. By default the same as in the xdirection. 
x 
the object of class 
filled 
if 
xyswap 
if 
... 
additional arguments that are passed on to 
Details

When the property is isotropic, the
x.mid
andy.mid
values are identical. This is for example the case for sediment porosity. 
When the property is anisotropic, the
x.mid
andy.mid
values can differ. This can be for example the case for the velocity, where in general, the value will differ between the x and y direction.
Value
A list of type prop.2D
containing:
x.mid 
property value in the xdirection defined at the middle of the grid cells; Nx * Ny matrix (where Nx and Ny = number of cells in x, y direction) 
y.mid 
property value in the ydirection at the middle of the grid cells; Nx * Ny matrix 
x.int 
property value in the xdirection defined at the xinterfaces of the grid cells; (Nx+1)*Ny matrix 
y.int 
property value in the ydirection at the yinterfaces of the grid cells; Nx*(Ny+1) matrix 
Note
For some properties, it does not make sense to use y.func
different
to func
. For instance, for volume fractions, AFDW.
For other properties, it may be usefull to have y.func
or
y.value
different from func
or value
, for instance
for velocities, surface areas, ...
Author(s)
Filip Meysman <filip.meysman@nioz.nl>, Karline Soetaert <karline.soetaert@nioz.nl>
Examples
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15  # Inverse quadratic function
inv.quad < function(x, y, a = NULL, b = NULL)
return(1/((xa)^2+(yb)^2))
# Construction of the 2D grid
x.grid < setup.grid.1D (x.up = 0, L = 10, N = 10)
y.grid < setup.grid.1D (x.up = 0, L = 10, N = 10)
grid2D < setup.grid.2D (x.grid, y.grid)
# Attaching the inverse quadratic function to the 2D grid
(twoD < setup.prop.2D (func = inv.quad, grid = grid2D, a = 5, b = 5))
# show
contour(log(twoD$x.int))
