The Grade options allow you to grade a whole line feature or between selected points. When selected, the pop-up menu shown to the right is displayed.
Averaging Feature Grades
The Average options allow you to use the heights of two existing feature points and apply a linear grade between them. The existing feature points must have a valid height, but the points in don’t have to.
The Average All option will grade a whole line feature using the heights at either end and the indicated feature cannot be closed. The Average Between option allows you to indicate two points on a line feature and grade the points between them.
Specifying Feature Grades
The From options allow you to specify a start point on a line feature and a grade that is to be applied to all or part of that line feature. The start point must have a valid point but the points to grade don’t have to.
The From All option will grade a whole line feature from an indicated endpoints. The From Between option will grade a line feature from an indicated start point to an indicated endpoint. This option will also calculate a new height for the endpoint.
After selecting either option and then indicating the end of a feature or the start and endpoints, the dialog box to the right will be displayed asking you to specify the grade that is to be used.
The Grade Value specifies the grade to be used and a drop list gives you some of the more common values. The Type group defines whether this value is in the form 1 in X or a percentage. The values in the drop list will change depending upon which type of grade has been selected. The Direction group defines whether the heights should increase or decrease from the start point.
Aligning Points in Features
The Align pop-up menu, shown to the right, gives you options to straighten features. It does this by projecting the existing feature points onto a user-defined baseline. The baseline points are also part of the feature in question.
The Align Between option will ask you to define the start and endpoints of the straightening. All points on the feature between the two indicated points will then be projected onto the line between those points.
Before Align Between
After Align Between
The Align All option will ask you to indicate a feature to straighten. The first and last points on the feature will then be used as the baseline for projection.
Before Align All
After Align All
The Align In-Fill option will ask you to indicate a feature line. The line needs to have at least a height at either end. This tool allows you to fill in null heights by linearly interpolating with the points either side.
|Before Grade In-Fill||After Grade In-Fill|
Note that aligning features will not work on closed features and that if the feature in question is not reasonably straight in the first place, you may get unpredictable results.