2DGridCreator
Creates a regular grid of points or rectangular polygons of a specified size, position, and coordinate system.
Typical Uses
-
Creating reference grids
-
Creating clipping polygons
How does it work?
The 2DGridCreator creates a single grid of regularly spaced features, which may be composed of:
-
rectangular polygons,
-
points at the corners of each cell, or
-
points at the center of each cell.
Cell size is specified by Column Width and Row Height, in the units of the specified Coordinate System.
A Starting Corner is selected (Lower Left is the default), along with a Starting X and Y Coordinate. Grid cells are calculated and numbered from this point accordingly for a specified number of columns and rows.
This transformer does not receive input features.
Examples
In this example, we will generate a grid along lines of latitude and longitude.
A 2DGridCreator is added to a workspace.
In the parameters dialog, we specify cell size, position, grid extent, and coordinate system. Type of Grid to Create is Polygons.
A grid of rectangular polygons is produced.
Note that the cells are numbered from the selected Starting Corner (Lower Left), starting at 0,0.
If Type of Grid to Create is Points (Corners), point features are placed at all cell corners.
Points (Centers) places a single point at the center of each cell, as shown here in conjunction with the Points (Corners) grid.
Usage Notes
Creating Boxes and Rectangles
Creating rectangular geometry is a common task. These transformers do so in a variety of ways.
Transformer |
Function |
---|---|
Creates one or more new features with box geometry of a specific size and position (when Geometry Object is Box). |
|
Replaces an existing feature’s geometry with a box of a specific size and position. |
|
Creates one rectangle that encompasses all features received. |
|
Individually replaces the geometry of each feature with a rectangle that covers its extents. |
|
Individually replaces the geometry of each raster feature with a rectangle that covers its extents (with various Extents Type options). |
|
Extracts the coordinate values that describe an individual feature’s bounding box (or cube) and stores them as attributes. |
|
Creates a series of regularly-spaced rectangles that span the extent of all features received (when Type of Grid to Create is Polygons). |
|
Creates a series of regularly-spaced rectangles of a specific size and position (when Type of Grid to Create is Polygons). |
|
Tiler and RasterTiler |
Do not create actual rectangles, but chop features into a series of rectangular tiles, specified in a similar fashion to the 2DGridAccumulator. |
Configuration
Input Ports
This transformer has no input ports.
Output Ports
A grid of polygon or point features as specified in parameters.
Parameters
Starting Corner |
Select the starting corner for calculating the grid and numbering the columns and rows.
|
||||||
Starting X Coordinate |
Specify the position of the Starting Corner on the x axis. |
||||||
Starting Y Coordinate |
Specify the position of the Starting Corner on the y axis. |
||||||
Number of Columns |
Specify the number of cells to create horizontally. |
||||||
Number of Rows |
Specify the number of cells to create vertically. |
||||||
Column Width |
Specify the cell width, in ground units. |
||||||
Row Height |
Specify the cell height, in ground units. |
||||||
Type of Grid to Create |
Select the grid type:
|
||||||
Coordinate System |
(Optional) Set the coordinate system of the generated grid. |
Column |
Name the attribute to contain column numbers, relative to the Starting Corner. Numbering starts at 0. |
Row |
Name the attribute to contain row numbers, relative to the Starting Corner. Numbering starts at 0. |
Editing Transformer Parameters
Using a set of menu options, transformer parameters can be assigned by referencing other elements in the workspace. More advanced functions, such as an advanced editor and an arithmetic editor, are also available in some transformers. To access a menu of these options, click beside the applicable parameter. For more information, see Transformer Parameter Menu Options.
Defining Values
There are several ways to define a value for use in a Transformer. The simplest is to simply type in a value or string, which can include functions of various types such as attribute references, math and string functions, and workspace parameters. There are a number of tools and shortcuts that can assist in constructing values, generally available from the drop-down context menu adjacent to the value field.
Using the Text Editor
The Text Editor provides a convenient way to construct text strings (including regular expressions) from various data sources, such as attributes, parameters, and constants, where the result is used directly inside a parameter.
Using the Arithmetic Editor
The Arithmetic Editor provides a convenient way to construct math expressions from various data sources, such as attributes, parameters, and feature functions, where the result is used directly inside a parameter.
Conditional Values
Set values depending on one or more test conditions that either pass or fail.
Parameter Condition Definition Dialog
Content
Expressions and strings can include a number of functions, characters, parameters, and more.
When setting values - whether entered directly in a parameter or constructed using one of the editors - strings and expressions containing String, Math, Date/Time or FME Feature Functions will have those functions evaluated. Therefore, the names of these functions (in the form @<function_name>) should not be used as literal string values.
These functions manipulate and format strings. | |
Special Characters |
A set of control characters is available in the Text Editor. |
Math functions are available in both editors. | |
Date/Time Functions | Date and time functions are available in the Text Editor. |
These operators are available in the Arithmetic Editor. | |
These return primarily feature-specific values. | |
FME and workspace-specific parameters may be used. | |
Creating and Modifying User Parameters | Create your own editable parameters. |
Dialog Options - Tables
Transformers with table-style parameters have additional tools for populating and manipulating values.
Row Reordering
|
Enabled once you have clicked on a row item. Choices include:
|
Cut, Copy, and Paste
|
Enabled once you have clicked on a row item. Choices include:
Cut, copy, and paste may be used within a transformer, or between transformers. |
Filter
|
Start typing a string, and the matrix will only display rows matching those characters. Searches all columns. This only affects the display of attributes within the transformer - it does not alter which attributes are output. |
Import
|
Import populates the table with a set of new attributes read from a dataset. Specific application varies between transformers. |
Reset/Refresh
|
Generally resets the table to its initial state, and may provide additional options to remove invalid entries. Behavior varies between transformers. |
Note: Not all tools are available in all transformers.
Reference
Processing Behavior |
Not applicable. |
Feature Holding |
Not applicable. |
Dependencies |
None |
Aliases |
|
History |
|
FME Community
The FME Community is the place for demos, how-tos, articles, FAQs, and more. Get answers to your questions, learn from other users, and suggest, vote, and comment on new features.
Search for all results about the 2DGridCreator on the FME Community.
Examples may contain information licensed under the Open Government Licence – Vancouver and/or the Open Government Licence – Canada.