I have a purely aesthetic layer which has arrow symbols. Some aren't showing up right because the line is too small. I have selected maybe 50 records where I need to extend this line by a given number (ex. 2 meters). The extend line tool only extends lines to a specified intersection, so this tool isn't what I'm looking for.
I've tried editing the shape length field but it won't let me.
Is there a simple way of doing this via field calculator or within the editor tool bar?
Best Answer
Well I think I've gotten it down for lines of any vertex count. I haven't attempted multipart lines since I've never messed with it in arcpy. The coding was made a bit more difficult since there isn't write access to the lastPoint property for Geometry objects. Instead of using the slope (which was my initial thought), I used the code from this SO question. It doesn't rely on trigonometry, so it should be slightly more efficient. The following code works by moving the endpoint of a line to a new coordinate that lies along the prolongation of a line from the last two vertices. I tested it on a shapefile.
I set the symbology to arrow at end for categories based on OID so that it will be easier to see the separation between features. Labeling was set to count vertices.![enter image description here](https://i.stack.imgur.com/4jyCh.png)