2DGridAccumulator

This transformer accepts any feature.

The grid of point or polygon features covering the bounding box area of the input features.

The input features may be partitioned into groups based on attribute values and one bounding box feature is output for each group. If you do not specify any Group By attributes, all input features will be processed together and a single bounding box will be output.

Note: How parallel processing works with FME: see About Parallel Processing for detailed information.

This parameter determines whether or not the transformer should perform the work across parallel processes. If it is enabled, a process will be launched for each group specified by the Group By parameter.

Parallel Processing Levels

For example, on a quad-core machine, minimal parallelism will result in two simultaneous FME processes. Extreme parallelism on an 8-core machine would result in 16 simultaneous processes.

You can experiment with this feature and view the information in the Windows Task Manager and the Workbench Log window.

Yes: This transformer will process input groups in order. Changes on the value of the Group By parameter on the input stream will trigger batch processing on the currently accumulating group. This will improve overall speed if groups are large/complex, but could cause undesired behavior if input groups are not truly ordered.

No: This is the default behavior. Processing will only occur in this transformer once all input is present.

Specifies how the grid size will be defined. Cell Size will enable the Column Width and Row Height parameters, while Number of Cells will enable the Number of Horizontal/Vertical Tiles parameters.

Chooses a starting corner for the purposes of numbering rows and columns. Also, when Size Type is Cell Size, the last row and/or the last column may extend beyond the bounds of the input features; here the “last” row or column is the one opposite the Starting Corner.

The Column Width and Row Height parameters specify in ground units the distance between output points in the grid or the width and height of the output polygons.

Important: If you want to choose attribute values as the Column Width and/or Row Height, only attributes selected in the Group By field are allowed. This is because all other attributes will be dropped. It also avoids the ambiguity that would arise if features within the same group had different values in these attributes: FME would not know which value to pick.

The Column Width and Row Height parameters specify in ground units the distance between output points in the grid or the width and height of the output polygons.

Important: If you want to choose attribute values as the Column Width and/or Row Height, only attributes selected in the Group By field are allowed. This is because all other attributes will be dropped. It also avoids the ambiguity that would arise if features within the same group had different values in these attributes: FME would not know which value to pick.

The Number of Horizontal Tiles and Number of Vertical Tiles parameters are required when the Size Type parameter is Number of Tiles, and allow you to specify how to tile the input data (for example, 5 horizontal tiles and 5 vertical tiles).

Important: If you want to choose attribute values as the Number of Horizontal Tiles and/or Number of Vertical Tiles, only attributes selected in the Group By field are allowed. This is because all other attributes will be dropped. It also avoids the ambiguity that would arise if features within the same group had different values in these attributes: FME would not know which value to pick.

The Number of Horizontal Tiles and Number of Vertical Tiles parameters are required when the Size Type parameter is Number of Tiles, and allow you to specify how to tile the input data (for example, 5 horizontal tiles and 5 vertical tiles).

Important: If you want to choose attribute values as the Number of Horizontal Tiles and/or Number of Vertical Tiles, only attributes selected in the Group By field are allowed. This is because all other attributes will be dropped. It also avoids the ambiguity that would arise if features within the same group had different values in these attributes: FME would not know which value to pick.

Choose point or polygon features.

Choosing Polygons will generate rectangular boxes with the specified column width and row height.

If Points (Corners) is selected, the corners of all the rectangles in the grid will be output. Points (Centers) will generate the middle point of each rectangle.

Note that there will be more features output for Points (Corners) than for either of Polygons and Points (Centers), since there will be one additional row and one additional column.

If Column Attribute or Row Attribute are specified, attributes will be added to each output tile that identify the position of that tile in the input raster. These indices are zero-based, beginning at the specified Starting Corner.

If Column Attribute or Row Attribute are specified, attributes will be added to each output tile that identify the position of that tile in the input raster. These indices are zero-based, beginning at the specified Starting Corner.