Velocity Options Tab

Figure 1 shows the Velocity Options tab of the Display Options form. This tab provides access to the velocity vector formatting options including scaling, display units, and many other formatting options. If the Scale Vectors check box is checked then the length of the velocity vectors will be proportional to the Scale factor. If this checkbox is not selected then a constant length vector with the correct rotation will be shown and the magnitude will be labeled next to the vector.

The Primary vector controls the vector display format of the currently loaded EFDC model's velocities. The Secondary vector controls either a second model's velocities (see Load Comparison Model) or data (see Load 2D Measured Data). To change the style of the vectors, LMC on the displayed vector.

Figure 1 ViewPlan Display Options: Velocity Options Tab.

When plotting the velocity vectors, EFDC_Explorer generally loops over the I and J components with the steps shown (e.g. "i Step"). If more control is needed for a project, the user may select the Velocity Labeling Locations file. This file is an ASCII file (DAT or P2D format) containing a list of XY coordinates. If selected, EFDC_Explorer loads the XY's and determines the corresponding cell list. If points are outside the model domain they are ignored. Then when plotting velocity vectors, only those cells in the list will be plotted.

Another feature of EE is the ability to be able to set velocity vectors at regular user-defined intervals independent of the grid and cell size. This is useful when a model varies from fine to coarse grid resolutions. In this case it is not helpful to have velocity arrows sparse in some areas and crowded in others. Selecting the Set Uniform Spacing button prompts the user for the delta X and delta Y for the velocity posting file, and subsequently prompts the user for the X and Y point of the lower left corner for the calculation of the spacing. By default this is the lower left corner. EE the creates a velocity map of the posting locations. The user may also load and save the labels and grid for

The user may also set the anchor point of vector: as start, midpoint or endpoint. This is done by clicking on vector arrow in Velocity Options which displays a form shown in Figure 2. Various other formatting options are available such as the color, taper and anchor point symbol.

Figure 2 ViewPlan Display Options: Vector Formatting Options