Dimensionality

This section describes the handling of dimensionality in WarpX.

Build Options

Dimensions	CMake Option
3D3V	WarpX_DIMS=3 (default)
2D3V	WarpX_DIMS=2
1D3V	WarpX_DIMS=1
RZ	WarpX_DIMS=RZ

Note that one can build multiple WarpX dimensions at once via -DWarpX_DIMS="1;2;RZ;3".

See building from source for further details.

Defines

Depending on the build variant of WarpX, the following preprocessor macros will be set:

Macro	3D3V	2D3V	1D3V	RZ
AMREX_SPACEDIM	3	2	1	2
WARPX_DIM_3D	defined	undefined	undefined	undefined
WARPX_DIM_1D_Z	undefined	undefined	defined	undefined
WARPX_DIM_XZ	undefined	defined	undefined	undefined
WARPX_DIM_RZ	undefined	undefined	undefined	defined
WARPX_ZINDEX	2	1	0	1

At the same time, the following conventions will apply:

Convention	3D3V	2D3V	1D3V	RZ
Fields
AMReX Box dimensions	3	2	1	2
WarpX axis labels	x, y, z	x, z	z	x, z
Particles
AMReX .pos()	0, 1, 2	0, 1	0	0, 1
WarpX position names	x, y, z	x, z	z	r, z
extra SoA attribute				theta

Please see the following sections for particle SoA details.

Conventions

In 2D3V, we assume that the position of a particle in y is equal to 0. In 1D3V, we assume that the position of a particle in x and y is equal to 0.