Creating, editing, renaming and deleting lines

This page covers:

• Creating lines
• Creating virtual lines
• Editing lines
• Renaming lines
• Deleting lines
• Changing the settings for an existing line

Creating editable lines

To create a new editable line:

1. On the Echogram tools toolbar, click the Line and Surface tool arrow and then click New Editable Line.
   
   - OR -
2. 
   On the Dataflow window, click New then Editable Line on the Shortcut menu (right-click).
3.  
4. - OR -
5.  
6. On the echogram, on the Shortcut menu and select New Line Pick.
   
2. In the Source section of the New Editable line dialog box, choose a source for the line:
   1. Existing line - automatically draw the new line using an offset (linear function or off-axis angle) of an existing line.
   2. Fixed depth (m) - automatically draw the new line at a fixed depth.
   3. Pick from current variable - automatically draw the new line using a line picking algorithm, see Line picking.
   4. None - hand draw the line using the line draw tool

3. Make a selection from the Visibility list.
4. Click Span gaps to close all breaks in the source line (if a source line is used).
5. In the Destination section:
   1. Choose the Create a new line option and enter a new for the new line, or
   2. Choose the Overwrite existing line option, and choose an existing line to replace

5. Click OK.
6. If you chose the None option as the source for the line, you must now create the line using the mouse. When the line is complete, choose Update Active Line from the Shortcut menu (right-click).
7. The new line is displayed on the echogram.

Notes:

• To create a new line by drawing with the mouse refer to detailed information for the Line and Surface tool.
• Subsequent line visibility management is conducted through the Lines page of the Variable Properties dialog box on a variable by variable basis.

Creating virtual lines

To create a new virtual line:

1. On the Echogram tools toolbar, click the Line and Surface tool arrow and choose New Virtual Line.
   
   -OR-
   On the Dataflow window, click New then Virtual line on the Shortcut menu (right-click).
   
   
2. On the New Virtual Line dialog box, enter the name of the virtual line in Name.
3. Select a Line operator from the Operator list.
4. Click OK.
5. On the Notes tab of the Line properties dialog box, enter Notes (if required) for the new virtual line.
6. Click the Operands tab (if available), select an operand.
7. Click the Operator name tab (if available), enter the settings for the virtual line.
8. Click OK.
9. The new virtual line is displayed on the echogram.

Notes:

• You can change the appearance of virtual lines on the Display page of the Line properties dialog box.

Editing lines

Virtual line

To edit an existing virtual line you can change its formula or other properties on the Line properties dialog box.

Editable line

Mouse

To edit an existing editable line using the mouse:

1. On the Echogram tools toolbar, click the Line and Surface tool arrow and select the desired line so that it becomes active.
2. Using your mouse, re-draw the section of the line that needs editing.
3. Click Update Active Line on the Shortcut menu (right-click).

Recalculate or repick a selection

This feature is useful when you want to modify sections of the line. The line may have been hand edited and you want to keep most, but not all of the changes.

When Repick Line is clicked, the line will be updated based on the settings in the Single beam tab of the Lines and Surfaces page of the EV File Properties dialog box. When Recalculate Line (...) is clicked, the line will be updated based on which option is selected for Line source in the Source page of the Line Properties dialog box.

To edit a selection on an existing editable line:

1. On the Echogram tools toolbar, click the Line and Surface tool arrow and select the desired line so that it becomes active.
2. Click the Line and Surface tool arrow and select Active Line Properties.
3. Click the Source page of Line Properties dialog box.
4. On the Source page select a line source from the Line source list, and enter any required settings.
5. Click OK.
6. Click a Selection tool.
7. Make a selection with the Vertical band tool on the active line.
8. On the Shortcut menu (right-click) select Recalculate Line (...) or Repick Line.

Notes:

• If there is no selection, Recalculate Line and Repick Line are applied to the whole line.
• Vertical band selections are recommended for the best results when using Recalculate Line and Repick Line.
• An editable line can specify itself as the Offset line for Line source: Offset from line.
• A display relative to an Echogram reference line may be useful for line verification. See also About lines: Echogram reference line.

Line properties

To edit an existing editable line using the lines properties:

1. On the Echogram tools toolbar, click the Line and Surface tool arrow and choose an editable line from the list.
   1. On the Echogram tools toolbar, click the Line and Surface tool arrow and select Active Line Properties.

-OR-

1. On the Dataflow window, click an editable line and on the shortcut menu select Line properties.
2. On the Extension tab, change the required settings to move the line.
   • Under Span gaps; select Span gaps when you want to close all breaks from the source line.
3. Click OK

To move an existing editable line in the range dimension:

1. Calculate the equivalent distance to move in the depth dimension:
   1. Read the Elevation of the transducer on the Geometry page of the Transducer Properties dialog box
   2. Multiply the range by the cosine of the elevation angle
2. Display the Line Properties dialog box.
3. In the Extension box:
   1. Under Offset click Linear function
   2. Under then add, type the distance (in meters) you would like to move the line by
4. Under Span gaps, select Span gaps when you want to close all breaks from the source line.
5. Click OK.

Notes:

• If you have more than one transducer defined in the EV file, they may have different elevations. Lines are available to all variables on all transducers and stored in depth space, not range space. You will have to consider the use to which your line is put in deciding which transducer provided the most applicable model of range to depth conversion. See About depth, range and altitude.
• To edit an existing line with the mouse refer to detailed information for the Line and Surface tool.
• Extend an editable line during live viewing with settings on the Source page of the Line Properties dialog box.

Renaming lines

You can rename a line or virtual line, using one of four methods:

1. On the Dataflow window select the line, on the Shortcut menu select Rename.
2. On the Dataflow window, select the line and press F2.
3. On the Dataflow window, select the line and select the line again to edit the line name. This process is different from using a double-click. See the Note below.
4. On the Notes page of the Line Properties dialog box, you can change the name in the Name box.

Note: The rate at which you can apply two consecutive single clicks will be affected by the value for Double-click speed on the Button page of Mouse Properties.

Deleting lines

To delete an entire line or virtual line:

1. Display the Dataflow window .
2. Display a view showing the line.
3. Select the line to delete.
4. On the Shortcut menu (right-click), click Delete.

To delete part of a line (you cannot delete part of a virtual line):

1. Click the Line and Surface tool arrow and choose the line from the list (this makes the line active).
2. Use one of the selection tools to select the part of line you wish to delete.
3. Choose Set Line Status from the Shortcut menu (right-click).
4. Choose None from the Line status list.

Note: The relationships of lines to variables can be displayed in the Dataflow window with the Line usage setting in the Relationship section of a View.

Changing an existing line

Change a depth

Entire line

1. Click the Line and Surface tool arrow and select New Editable Line.
2. In the New Editable Line dialog box.
   1. Under the Destination section, select Overwrite existing line and choose the line of interest from the list.
   2. Under the Source section, choose to either use an Offset (Linear function or Off-axis angle) or set an entirely new Fixed depth.

Part of a line

Refer to Editable line: Recalculate or Repick a selection.

See also

About lines
About the Set Active Line dialog box
About off-axis angle line offsets
About Line Status
Line and Surface tool