Smoothing with expand_dist and expand_factor

pyremap provides a unique capability for controlled smoothing when writing out the destination mesh descriptor. This is achieved through the use of two optional attributes: expand_dist and expand_factor. These attributes can be specified either as part of the destination descriptor or as attributes of the remapper, which will then pass them along to the destination descriptor.

Attributes Overview

• expand_dist: Specifies a distance in meters by which each grid cell is expanded. This can be provided as:

  • A single float value, which applies the same expansion distance to all grid cells.

  • A numpy.ndarray with the same size as the latitude and longitude coordinates of the mesh or grid, allowing for cell-specific expansion distances.

• expand_factor: Specifies a fraction of the cell size by which to expand each grid cell. This can also be provided as:

  • A single float value, applying a uniform expansion factor to all grid cells.

  • A numpy.ndarray with the same size as the latitude and longitude coordinates of the mesh or grid, enabling cell-specific expansion factors.

Note: The default values are expand_dist = 0.0 and expand_factor = 1.0, which result in no smoothing.

Usage and Behavior

These attributes are particularly useful for producing highly controlled smoothing as part of the remapping process. By expanding grid cells either by a fixed distance (expand_dist) or by a fraction of their size (expand_factor), users can fine-tune the smoothing effect to meet specific requirements.

Important Notes

1. Combination with the conserve Method: The expand_dist and expand_factor attributes must be used in combination with the conserve remapping method. This is because they leverage the area-weighted interpolation mechanism inherent to this method.

2. Flexibility: The ability to specify these attributes as either floats or numpy.ndarray fields provides flexibility for both uniform and non-uniform smoothing across the grid.

By using these attributes, pyremap enables advanced control over the remapping process, making it a powerful tool for applications requiring precise smoothing adjustments.