It is often desirable to view and edit the Manning's n values or roughness heights (k values) for several cross sections all at the same time. From the Geometric Data editor, the user can select Manning's n or k values from the Tables menu item. Once this option is selected, a window will appear as shown in Figure 5-70.
As shown in Figure 5-70, the user has the options of selecting either n or k values to be used as the roughness coefficient, add a constant to one or more of the n or k values, multiply a group of n or k values by a factor, or change a group of n or k values to a specific value. Additionally, cut, copy, and paste buttons are provided to pass data to and from the Windows Clipboard. The user can optionally select to view all regions of the cross sections, the left overbank only, the main channel only, the right overbank only, or both overbanks. The main channel roughness coefficients are shown shaded in green in order to make it easier to distinguish between overbank and channel roughness coefficients in the table.
To add a constant to a group of n or k values, the user must first highlight the values that they would like to change. Highlighting is accomplished by placing the mouse in the upper left cell of the desired cells to highlight, then press the left mouse button and drag the cursor to the lower left corner of the desired cells to highlight. When the left mouse button is released, the cells that are selected will be highlighted (except the first cell). Once the user has highlighted the desired cells to be modified, press the Add Constant button. This will bring up a pop up window, which will allow the user to enter a constant value that will be added to all cells that are highlighted.
Figure 5 70. Manning's n Data View and Editing Table
To multiply a group of n or k values by a factor, the user first highlights the desired cells. Once the cells are highlighted, pressing the Multiply by a Factor button will bring up a pop up window. This window allows the user to enter a value that will be multiplied by each of the highlighted cells.
To set a group of n or k values to the same number, the user must first highlight the values that they would like to change. Once the cells are highlighted, pressing the Set Values button will bring up a pop up window. This window will allow the user to enter a specific n or k value, which will replace all of the highlighted values.
The last option (Replace) is to find and replace a specific number with a new number. When this option is selected the user is asked to put in a number to search for and also a number to replace it with. This option only searches and replaces data in highlighted fields.
An additional option is the Reduce Channel to a Single n-Value. This option will find the Manning's n or k value at the midpoint between the main channel bank station, then change the entire channel to a single roughness coefficient equal to that midpoint value.
The user can also go directly into the table and change any individual values.