Data Sets Dialog Box

Data sets are managed through the Data Sets dialog box. To display the Data Sets dialog box, select Data|Edit Data Sets…

Data sets have a two-dimensional or three-dimensional array of values. In PHAST, these values are assigned either to elements or to nodes and the data sets can apply either to the entire grid or a projection of the grid in the top, front, or side views. (These values correspond to “properties” as used in section 4.2.1.3 of the PHAST manual (Parkhurst and others, 2004). In MODFLOW and WellFootprint, these values are assigned to cells in the entire grid or to cells in a projection of the grid or mesh in the top view. In SUTRA, these values are assigned either to elements or to nodes in the mesh or a projection of the mesh in the top view. In this report, “properties” do not necessarily refer to spatially distributed data.) This section describes each of the properties of a data set that the user can change.

All of the data sets are displayed in a tree-view control on the left side of the Data Sets dialog box. When a data set is selected in the tree-view. its properties are displayed in the controls on the right side of the Data Sets dialog box. The data sets include those required by PHAST, MODFLOW,, MODPATH, ZONEBUDGET, MT3DMS or MT3D-USGS, SUTRA, or Well Footprint along with data sets that the user has created. If a data set is sometimes required by the model but is not being used in the current project, it is displayed in the tree control under Data Sets|Optional. Data sets that are required by the current model are under Data Sets|Required. Each data set has several properties: its name, whether or not it is visible, type, orientation (top, front, side, or 3-D), where it is evaluated (nodes or elements), its units, its formula, and, for 2-D data sets, its interpolation method. For data sets used directly by a model (table 7 and table 8), the name, type, orientation, and where it is evaluated cannot be changed. For data sets created by the user, these properties can be changed. For some data sets that are used directly by PHAST, the user can use a special PHAST-style interpolation method (p. 16).

To create a new data set, click the Add button in the Data Sets dialog box. Clicking the Add button, adds a new data set at the end of the list. To delete a data set, select data set in the tree-view and then click on the Delete button. (Users cannot delete data sets that are used directly by a model.)

The Name of a data set is used to identify it in formulas for other data sets and when exporting the corresponding model data set (if there is one). A name must begin with either the underscore character a letter in either upper- or lower-case characters. Subsequent characters must be the underscore character, letters in either upper- or lower-case characters, or the digits 0 through 9. Spaces are not allowed in the names of data sets. Data Set names are case insensitive. Thus, “A_NAME”, “a_name”, and “A_Name” are all equivalent. Unicode characters are allowed in data set names. However, when data set names are printed in comments in model input files, Unicode characters will be converted to ASCII characters.

Each data set must have a Type that indicates what kind of data are stored in it. Valid types are "Real," "Integer," "Boolean," and "Text.” These types represent real numbers, integers, true/false values, and text, respectively. Most of the data sets built into ModelMuse are "Real" or "Integer.” The "Active" data set is "True/False.” No built-in data sets are "Text.”

The Orientation of a data set determines the shape of a data set. The possible choices are 2-D Top, 2-D Front, 2-D Side, and 3-D. Most data sets have an Orientation of 3-D. A data set with a 2-D Top orientation has a single layer but multiple columns and rows. A data set with a 2-D Front orientation has a single row but multiple columns and layers. A data set with a 2-D Side orientation has a single column but multiple rows and layers. A data set with a 3-D orientation has multiple columns, rows, and layers. 2-D Front and 2-D Side data sets can only be used with PHAST.

If Evaluated at (the evaluation location) is set to Elements, then the values in the data set correspond to elements in the model grid and are evaluated at the centers of elements. If Evaluated at is set to Nodes then the values in the data set correspond to nodes in the model grid. For orientations of 2-D Top, the data set values correspond to the elements or nodes in a 2-D projection of the model grid from above. Similarly for 2-D Front and 2-D Side, the data set values correspond to the elements or nodes in a 2-D projection of the model grid from the front or side, respectively.

The Units of a data set are meant to serve as a reminder to the user. The units do not affect how values are computed except if the units are set to degrees or radians. See Specifying Angles for SUTRA for more information.

The Default formula of a data set is a mathematical expression that defines the value that will be applied to each location in a data set unless a value for that location is specified in some other way (such as being set by objects). A formula may be a simple numerical value or it can express much more complex relationships. See the section on Formulas for more information.

If a data set is a two-dimensional data set, it can use one of the 2-D Interpolation methods in conjunction with one or more objects to define the values of a data set. If an interpolation method is being used with a data set, the Anisotropy edit box related to that interpolation method becomes enabled in the bottom part of the dialog box when the data set is selected. Seven interpolation algorithms are available in ModelMuse. From fastest to slowest these are

1.Nearest Point

2.Triangle Interp.

3.Fitted Surface

4.Nearest Neighbor

5.Nearest

6.Point Inv. Dist. Sq.

7.Inv. Dist. Sq.

See Interpolation Methods for more information;

If PEST is activated, the PEST Parameters tab will be visible for some data sets. The PEST Parameters tab has a single control, the Use PEST parameters checkbox. If the Use PEST parameters checkbox is checked, a new data set will be created when the Apply button is clicked. The new data set will have the same name as the data set for which Use PEST parameters was checked except that "_Parameter_Names" will appended to the name. The new data set will be a text data set. The new data set is used to designate cells (MODFLOW) or nodes or elements (SUTRA) to which a particular PEST parameter will apply. If the data set for which the Use PEST parameters checkbox is checked is a required data set, the values of the model input data set to which it corresponds will be updated by PEST during the parameter estimation process. If the data set for which the Use PEST parameters checkbox is checked is not a required data set, it will be exported as an array whose values will be updated by PEST and whose values can be used in model features.

The optional Comment is provided for the use by the user. It is also displayed in the Color Grid and Contour Data panes of the Data Visualization dialog box. When importing new data sets, a comment for the data may be automatically generated describing the source of the data, the data range, or other information. (See also: Select Model Results to Import dialog box.)

The Associated model data lists the names of the model input data sets correspond to the data set. The user can not assign the Associated model data.

If the data set is one of the PHAST data sets with which PHAST-style interpolation can be used, the Use PHAST-style interpolation for all cells checkbox will be enabled when the data set is selected. If the user checks this checkbox, the other controls related to PHAST-style interpolation will become enabled. See PHAST-Style Interpolation.

In a new ModelMuse project, the only data sets present are those required by PHAST (table 7) or those required by MODFLOW (table 8). However, the user can create additional data sets for his or her own purposes. One reason to create a data set would be to use it in a formula for one of the data sets required by PHAST. For example, the user could create a 2-D Top data set that represented the hydraulic conductivity of a particular geologic unit. It could then be used to assign Kx for just those elements that were part of that geologic unit. The Biscayne Bay aquifer example illustrates this process.

In MODFLOW models, some data sets are set using MODFLOW parameters, zone arrays and multiplier arrays instead of with formulas and objects. The parameters are defined in the MODFLOW Packages and Programs dialog box.

Parameters can also be edited in the Manage Parameters dialog box.

If Use Zone is checked in the MODFLOW Packages and Programs or Manage Parameters dialog boxes, a boolean data set will be created that can be used to determine where the parameter applies. The parameter will apply everywhere where the data set is true. The name of the data set will be the name of the parameter followed by "_Zone.." If Use Zone is not checked, the parameter will apply everywhere.

If Use Multiplier is checked in the MODFLOW Packages and Programs or Manage Parameters dialog boxes, a real-number data set will be created that can be used to determine how the parameter Value is related to the input. The name of the data set will be the name of the parameter followed by "_Multiplier." The parameter value will be multiplied by the values in the multiplier data set for each cell to determine the input value for MODFLOW at that cell.

If more than one parameter of the same type applies to the same cell, the input value for MODFLOW will be the sum of the input values determined for that cell for all the parameters that apply to the cell. For example, suppose that there are two HK parameters defined: HK1 and HK2. They have Values of 10 and 20 respectively. If they both apply to the cell in column 1, row 1, layer 1 and neither has multiplier data sets, the hydraulic conductivity for that cell would be 10 + 20 = 30. Now suppose that the multiplier for HK1 was 5 at that cell. The hydraulic conductivity for that cell would be 10*5 + 20 = 70.