SMS:Datasets

A dataset is a set of values associated with each node, cell, vertex, or scatter point in an object. A dataset can be steady state (one value per item, one time step) or transient (one value per item, multiple time steps). The values in the dataset can be scalar values or vector values. Certain types of objects in SMS have an associated list of scalar datasets and a list of vector datasets. Each of the following objects in SMS can have both scalar a vector datasets:

• Scattered Datasets
• 2D Meshes
• 2D Cartesian Grids
• Particle Sets
• 1D Grids

Datasets are used for both pre- and post-processing of models. For example, a scalar dataset associated with a 2D mesh can represent starting values of elevations or initial water surface elevations for a surface water modeling problem. Another dataset associated with the same mesh may represent computed water surface values. Datasets can be used to generate contours, vector plots, functional surfaces and animation sequences. The commands for manipulating datasets are located in the Current Model's Data menu.

Generating Datasets

Data sets can be generated in a variety of ways such as:

• Output from a surface water model (water level, velocity, concentration, transport, etc.)
• Tabular values in a text file entered by the user or exported from another application such as a GIS
• Created by interpolating from a scatter point set to a grid, or mesh
• Generated by performing mathematical operations on existing datasets with the Data Calculator

One advantage of the dataset approach for managing information is that it facilitates transfer of information between different models with differing resolution. This is accomplished through scatter sets and interpolation. Grids and meshes can be converted to a 2D scatter set. When an object is converted to a scatter set, all scalar datasets associated with the object are copied to the new scatter set. The datasets can then be transferred from the scatter set to other objects of any type using interpolation.

Right Click Menus

Datasets are displayed and managed in the Project Explorer. Right clicking on a data set invokes the right click menu which consists of a list of commands that can be performed on the dataset.

Dataset Information

The dataset info dialog allows the user to examine statistical properties of the dataset.

Active Dataset

Each module in SMS has a set of values designated as the "active dataset." The active data set is an important part of model visualization in SMS. Each time the display is refreshed, the contours and other display features are generated using the active dataset. Left-clicking on a solution or dataset in the Project Explorer makes that item "active". The icons used to identify the different datasets shown in the Project Explorer are as follows:

Dataset Type	Inactive Icon	Active Icon
Elevation	File:SMS Inactive Elevation Data Set.bmp	File:SMS Active Elevation Data Set.bmp
Scalar	File:SMS Inactive Scalar Data Set.bmp	File:SMS Active Scalar Data Set.bmp
Vector	File:SMS Inactive Vector Data Set.bmp	File:SMS Active Vector Data Set.bmp

If the active dataset is transient then the time steps are displayed in the Time Step Window.

Solutions

Solutions are output from a numerical model that SMS supports. Solutions are shown in the Project Explorer as a folder. If a solution is transient then the time steps are displayed in the Time Step Window. The solution may contain text files such as the *.out and *.prt files produced by a model. These files can viewed by right clicking on the item and selecting View File from the pop up menu, or you can double click on the item.

Folder

The datasets and solutions are organized by folders. The user can create new folders and move datasets, solutions, and folders to other folders anywhere on the Project Explorer. Folders can be created by right clicking on the certain items in the Project Explorer and selecting New Folder in the menu. A dataset or folder can be deleted simply by selecting the folder and selecting the Delete key or by right-clicking on the item and selecting the Delete option in the corresponding pop-up menu.

Related Topics

• Layout of the Graphical Interface