Difference between revisions of "Post-Processing:Data tree"

Latest revision as of 15:18, 17 April 2008

The data tree is a new feature in WMS 7.1. It serves as a means of organizing all the data sets associated with the several models and modules in WMS. In the 2D Grid module, the data tree serves to store and modify the attributes of all gridded data sets. In this capacity is replaces the data browser dialog in WMS 6.1. However, it can do much more than the data browser did.

Data Sets

The data tree serves as a manager for all of the gridded data sets and link / node data sets that have been read into WMS. When other modules are active the data tree references TINs, DEMs, Scatterpoint sets, Coverages, and other data storage types. The main strength of the data tree lies in consolidating access to the data sets. Right-clicking on a data set brings up a list of options that are available for that data type. In the 2D Grid module, when a data set is right-clicked, a right-click menu comes up that offers the following options: exporting the data set, renaming the data set, viewing the properties of the data set, viewing the values of the data set, setting the contour options for the data set, and setting the data set to be the elevation data set.

Index Maps

Unique to GSSHA are special data sets that serve as index maps that link simulation parameters to their spatial distribution. The principle means of modifying and creating index maps is in the Index Map dialog but the index maps are now also able to be accessed through the data tree. When an index map has been created or read into WMS a folder appears in the data tree, named Index Maps, that contains all of the index maps for the simulation. Index maps can then be treated like regular data sets; they can be contoured, renamed, deleted, and edited.

Solutions

While solutions are not new to GSSHA, being able to work with them in WMS is a new feature. Accessible from the GSSHA menu in the 2D Grid module is the command Read Solution... which looks for a GSSHA project file and then reads in all of the associated data sets and lumps them together into a solution folder in the data tree. Solution folders are identified by a lowercase “s” on the folder. All of the data sets in the folder are treated as regular data sets. Organizing the data sets into a solution allows several solutions to be in memory at the same time. Several dialogs look for solutions and the associated data sets to set up and display output graphs. Along with the regular data sets, the summary file for the project is also accessible for each solution by double-clicking the summary file tree item under the solution folder.

Individual solution output time series data for a cell may be viewed from the Solution Results dialog accessed from the Feature Point/Node Type dialog. This dialog will only show the output data set time series for the cell that underlies the feature point selected. To compare the solution output at a cell with observed data, select the Observations button on the Feature Point/Node Type dialog.

Contour Options

New to WMS 7.1 is the use of OpenGL code for much better graphics display. OpenGL is a 3D graphics library that makes displaying graphics in WMS much faster and more efficient. The grid display routines in WMS have been enhanced with a better interpolation scheme that allows for a much smoother grid display as well as taking advantage of the strengths of OpenGL. The contouring routines have been redone to also use the enhanced grid and OpenGL, which results in faster, smoother surfaces that are continuous color contoured as opposed to step color contoured as in WMS 6.1. Also, OpenGL shades surfaces automatically, so this option is always turned on when the contour is color filled.

Cell filling the grid has been an option since WMS 6.1. However, WMS 7.1 allows much more flexibility in visualizing the output and input to GSSHA through cell filling by making it into part of the contour options. Simply make sure the cell filled radio button is selected and each cell will be filled with the color that represents the data point at the center of the cell. This color is taken from a smooth (linearly interpolated) color ramp. Cell filling is independent of block-style cell display, which is set in the display options.

One of the new features of the data tree is that it allows access to individual contour options for each data set. When a data set is read in it is given the default set of contour options that can then be modified by right clicking on the data set in the data tree. Whichever data set is active is the only data set contoured. The contours for the grid come from the active data set whereas the elevations of the grid come from the current elevation data set. This setup allows the results of a GSSHA simulation to be displayed as contours on a grid that is shaped like the underlying terrain. In the data tree the active data set is shown with a yellow icon and bold lettering and the current elevation data set has (elev) after the name of the data set.

Related Topics

GSSHA Wiki Main Page
Primer Main Page

Post-Processing

Output control

Data tree

Visualizing results