The gwb-grid app

The gwb-grid app#

While the gwb-dat app is great at providing individual points, providing gridded output can be very useful especially when visualizing the result. This is exactly what the gwb-grid app does. It creates a grid with the values requested and outputs it as a vtu file. Using gwb-grid is very similar to using gwb-dat: gwb-grid world_builder_file.wb grid_info.grid. The only difference is that you now provide a .grid file instead of a .dat file.

A grid file consists of a number of parameters. Each parameter should start with a name (no spaces) followed by an equal sign, followed by the value. The available parameters are:

  1. grid_type: Options are cartesian, sphere, chunk and annulus.

  2. dim: dimension, either 2 or 3.

  3. composition: how many compositions

  4. vtu_output_format: Either ASCII for readable output or RawBinaryCompressed for compressed output.

  5. x_min: either the minimum x value or minimum longitude.

  6. x_max: either the maximum x value or maximum longitude.

  7. y_min: either the minimum y value or minimum latitude.

  8. y_min: either the maximum y value or maximum latitude.

  9. z_min: either the minimum z value or minimum radius.

  10. z_min: either the maximum z value or maximum radius.

  11. n_cell_x: either the number of cells in the x or longitude direction.

  12. n_cell_y: either the number of cells in the y or latitude direction.

  13. n_cell_z: either the number of cells in the z or radius direction.

An example of a grid file is the following:

 1# output variables
 2grid_type = chunk
 3dim = 3
 4compositions = 2
 5
 6# domain of the grid
 7x_min = -5
 8x_max = 45 
 9y_min = -5
10y_max = 40 
11z_min = 5611e3
12z_max = 6371e3
13
14# grid properties
15n_cell_x = 100 
16n_cell_y = 80
17n_cell_z = 32

When you run it, it will produce a vtu file with the same name in the directory you run it from.

More examples can be found in the tests/gwb-grid/ directory.