GENIE Gridspec - Revision history

Genie-user: /* Draft gridspec */

2007-04-02T15:28:22Z

Draft gridspec

Genie-user: /* Draft gridspec */

2007-04-02T15:25:51Z

Draft gridspec

Genie-user: /* Gridspec proposal */

2007-04-02T15:21:29Z

Gridspec proposal

Genie-user: /* Known issues */

2007-03-06T18:05:26Z

Known issues

Genie-user: /* Draft gridspec */

2007-03-02T12:38:11Z

Draft gridspec

Genie-user: /* Gridspec introduction */

2007-03-01T14:47:11Z

Gridspec introduction

Genie-user: /* Known issues */

2007-02-27T17:58:16Z

Known issues

Genie-user: /* Known issues */

2007-02-27T17:57:40Z

Known issues

Genie-user: /* Element cross-referencing */

2007-02-27T17:54:33Z

Element cross-referencing

Genie-user: /* Element cross-referencing */

2007-02-27T17:52:30Z

Element cross-referencing

@@ Line 27: / Line 27: @@
 ==Draft gridspec==
-The XML gridspec implementation below is based very closely on Balaji's gridspec proposal.  For more detailed information please refer to [http://www.earthsystemcurator.org/index.php?option=com_content&task=view&id=38&Itemid=74 gridspec proposal] itself.
+The XML gridspec implementation below is based very closely on Balaji's gridspec proposal.  For more detailed information please refer to the [http://www.earthsystemcurator.org/index.php?option=com_content&task=view&id=38&Itemid=74 gridspec proposal] itself.
 The draft XML gridspec implementation is available for download here (the example is very simple at the moment - it doesn't illustrate the more advanced features of the gridspec):

@@ Line 27: / Line 27: @@
 ==Draft gridspec==
-The XML gridspec implementation below is based very closely on Balaji's gridspec proposal, UML diagrams for which can be found [http://curatordb.cvs.sourceforge.net/*checkout*/curatordb/curator/curator-nmm/grid/gridspec_model.gif here (gridspec model)] and [http://curatordb.cvs.sourceforge.net/*checkout*/curatordb/curator/curator-nmm/grid/gridspec_details.gif here (gridspec details)].  For more detailed information please refer to Balaji's [http://curatordb.cvs.sourceforge.net/*checkout*/curatordb/curator/curator-nmm/grid/gridstd.pdf gridspec PDF document].
+The XML gridspec implementation below is based very closely on Balaji's gridspec proposal.  For more detailed information please refer to [http://www.earthsystemcurator.org/index.php?option=com_content&task=view&id=38&Itemid=74 gridspec proposal] itself.
 The draft XML gridspec implementation is available for download here (the example is very simple at the moment - it doesn't illustrate the more advanced features of the gridspec):

@@ Line 19: / Line 19: @@
 ==Gridspec proposal==
-A [http://www.earthsystemcurator.org/index.php?option=com_content&task=view&id=38&Itemid=74 gridspec proposal] is currently being worked on by V. Balaji (GFDL).  The proposal currently consists of a [http://curatordb.cvs.sourceforge.net/*checkout*/curatordb/curator/curator-nmm/grid/gridstd.pdf PDF document] that describes the proposed standard, implemented as an extension to the NetCDF [http://www.cgd.ucar.edu/cms/eaton/cf-metadata/CF-current.html Climate and Forecast (CF) conventions], and a couple of UML class diagrams that provide a diagrammatic overview of the proposed grid schema.
+A [http://www.earthsystemcurator.org/index.php?option=com_content&task=view&id=38&Itemid=74 gridspec proposal] is currently being worked on by V. Balaji (GFDL).  The proposal currently consists of a document that describes the proposed standard, implemented as an extension to the NetCDF [http://www.cgd.ucar.edu/cms/eaton/cf-metadata/CF-current.html Climate and Forecast (CF) conventions], and a couple of UML class diagrams that provide a diagrammatic overview of the proposed grid schema.
 As part of the work to create a version of the [[GENIE_Coupling|GENIE ESM framework using the PRISM coupler]] (OASIS) using the [[GENIE_BFG|Bespoke Framework Generator (BFG)]] tool, a working implementation of Balaji's grid schema proposal is being developed.  This gridspec implementation will be used to describe the grids used by individual GENIE models, allowing BFG to generate automatically the PRISM grid initialisation code for each model required for OASIS coupling.  A draft of this gridspec is presented below.

← Older revision		Revision as of 18:05, 6 March 2007
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	* Gridspec needs to be extended - e.g. missing cell types for different discretisations. The use of base types/base classes should make the gridspec easy to extend. This is best done by people who are experts on the different grids in question.		* Gridspec needs to be extended - e.g. missing cell types for different discretisations. The use of base types/base classes should make the gridspec easy to extend. This is best done by people who are experts on the different grids in question.
		+
		+	* Horizontal coordinate systems are represented by an enumeration; vertical coordinate systems by a type hierarchy. This is as in the [http://curatordb.cvs.sourceforge.net/checkout/curatordb/curator/curator-nmm/grid/gridspec_details.gif "gridspec details"] UML diagram provided by Balaji. It may be more consistent and flexible to use type hierarchies for both.

	==See also==		==See also==

@@ Line 29: / Line 29: @@
 The XML gridspec implementation below is based very closely on Balaji's gridspec proposal, UML diagrams for which can be found [http://curatordb.cvs.sourceforge.net/*checkout*/curatordb/curator/curator-nmm/grid/gridspec_model.gif here (gridspec model)] and [http://curatordb.cvs.sourceforge.net/*checkout*/curatordb/curator/curator-nmm/grid/gridspec_details.gif here (gridspec details)].  For more detailed information please refer to Balaji's [http://curatordb.cvs.sourceforge.net/*checkout*/curatordb/curator/curator-nmm/grid/gridstd.pdf gridspec PDF document].
-The draft XML gridspec implementation is available for download here:
+The draft XML gridspec implementation is available for download here (the example is very simple at the moment - it doesn't illustrate the more advanced features of the gridspec):
 * [http://www.met.reading.ac.uk/~ian/gridspec/gridspec.xsd Gridspec schema file (gridspec.xsd)]

@@ Line 15: / Line 15: @@
 * The gridspec is designed to be extensible so that it can be used to describe many different types of grid, both extant and future.
-The gridspec should be able to describe grids at different spatial resolutions, and of different shapes and structures.  It should be able to cover, or be easily extended to cover, as wide a range of grids as possible.
+The gridspec should be able to describe grids at different spatial resolutions, and of different shapes and structures.  It should be able to cover, or be easily extended to cover, as wide a range of grids as possible.  The gridspec should also be of use for both model control (coupling) and output (reporting).
 ==Gridspec proposal==

@@ Line 77: / Line 77: @@
 * How and where should halo regions be described for grids that are split up into multiple "tiles" for parallel processing?  (Is this something the gridspec should cover?)
-* How should exchange grids be specified for grid tiles where coordinate axes are specified instead of individual cells (e.g. for regular grids like those used by IGCM and GOLDSTEIN)?  Currently, exchange grid cells consist of references to individual cells in the overlapping grids.  A similar problem may exist for boundary anchor points.
+* How should exchange grids be specified for grid tiles where coordinate axes are specified instead of individual cells (e.g. for regular grids like those used by IGCM and GOLDSTEIN)?  Currently, exchange grid cells consist of references to individual "parent" cells in the overlapping grids.  A similar problem may exist for boundary anchor points.
 * Gridspec needs to be extended - e.g. missing cell types for different discretisations.  The use of base types/base classes should make the gridspec easy to extend.  This is best done by people who are experts on the different grids in question.

@@ Line 75: / Line 75: @@
 * Cell vertex data is potentially duplicated - many cells may share vertices.  A list of vertices should be associated with a tile rather than a cell, then each cell contains ''references'' to these vertices rather than the vertices themselves, as is done currently for cell edges (defined by refs to two vertices, rather than duplicating the vertices themselves).
-* How and where should halo regions be described for grids that are split up into "tiles" for parallel processing?  (Is this something the gridspec should cover?)
+* How and where should halo regions be described for grids that are split up into multiple "tiles" for parallel processing?  (Is this something the gridspec should cover?)
 * How should exchange grids be specified for grid tiles where coordinate axes are specified instead of individual cells (e.g. for regular grids like those used by IGCM and GOLDSTEIN)?  Currently, exchange grid cells consist of references to individual cells in the overlapping grids.  A similar problem may exist for boundary anchor points.

@@ Line 51: / Line 51: @@
 ===Element cross-referencing===
-Cross-referencing is used to avoid duplicate or redundant data in the XML gridspec.  The gridspec uses "ID" attributes to identify elements that might be referenced from elsewhere in the gridspec.  The attributes use the XML schema ''xs:ID'' type, which ensures that IDs are unique across a gridspec instance file.  Note that this will only work as intended once the gridspec is split up into "child" schemas and instance files for mosaics, tiles and contact regions - see [[GENIE_Gridspec#Known_issues|Known issues]].  The following elements currently have ID attributes (not shown in the diagrams):
+Cross-referencing is used to avoid duplicate or redundant data in the XML gridspec.  The gridspec uses "ID" attributes to identify elements that might be referenced from elsewhere in the gridspec.  The attributes use the XML schema ''xs:ID'' type, which ensures that IDs are unique across a gridspec instance file.  Note that this will only work as intended once the gridspec is split up into "child" schemas and instance files for mosaics, tiles and contact regions - see [[GENIE_Gridspec#Known_issues|"Known issues"]].  The following elements currently have ID attributes (not shown in the diagrams):
-* [[GENIE_Gridspec_Diagrams_Mosaic|Mosaicgrid]] - i.e. tiles and mosaics
+* [[GENIE_Gridspec_Diagrams_Mosaic|Mosaicgrids]] - i.e. tiles and mosaics
 * Cells - e.g. [[GENIE_Gridspec_Diagrams_UnstructuredCell|Unstructured cell]]
 * Points - e.g. the vertices used by [[GENIE_Gridspec_Diagrams_UnstructuredCell|unstructured cells]]
@@ Line 60: / Line 60: @@
 Elements with IDs are referenced by other elements using the XML schema ''xs:IDREF'' type.  The following elements contain references to elements elsewhere in the schema:
-* Edges - contain references to vertices - see [[GENIE_Gridspec_Diagrams_UnstructuredCell|Unstructured cell]]
+* Edges - contain references to vertices - see [[GENIE_Gridspec_Diagrams_UnstructuredCell|"Unstructured cell"]]
-* Tilespecs - a "fully-qualified tile ID" consisting of a reference to a single tile together with references to all the tile's parent mosaics - see [[GENIE_Gridspec_Diagrams_ContactRegion|contact regions]]
+* Tilespecs - a "fully-qualified tile ID" consisting of a reference to a single tile together with references to all the tile's parent mosaics - see [[GENIE_Gridspec_Diagrams_ContactRegion|"Contact region"]]
-* Parent cells - contain a reference to the tilespec and a reference to the cell within the tile - see [[GENIE_Gridspec_Diagrams_Overlap|Overlap]]
+* Parent cells - contain a reference to the tilespec and a reference to the cell within the tile - see [[GENIE_Gridspec_Diagrams_Overlap|"Overlap"]]
-Cross-referencing should also be used to avoid duplication of vertices shared between unstructured cells (see [[GENIE_Gridspec#Known_issues|Known issues]]), and may be used elsewhere in the gridspec in future.
+Cross-referencing should also be used to avoid duplication of vertices shared between unstructured cells (see [[GENIE_Gridspec#Known_issues|"Known issues"]]), and may be used elsewhere in the gridspec in future.
 ==Known issues==