How to extend a straight line by an exact length?

A user asked how he could use PC-MAPPER to extend a straight line by 2 meters.

There are a few ways to accomplish this.

1. Compute new position

Create a Point Feature Topic.

Note the plane coordinates of the last node on the straight line.

Use Map/Add Point by Mouse to add a Point to the Point Feature Topic.

Edit the coordinates of the Point Feature so its position will extend the line 2 meters in the direction of that line. Use the Pythagorian rule to compute the coordinates of the desired location.

Then select the Line Feature and use Edit/Insert Node to add the position of the newly created point as a node of the line.

2.  CoGo/Traverse

Create a Point Feature Topic.

Select the Line Feature and use Utilities/Disconnect Line to Points and select the Point Feature Topic as the topic for the two points.

Do not mark the checkbox for “Delete the original Feature”.

Now we have two points that we can use for the Traverse function.

Select CoGo/Traverse. Select the end point of the line as the From Point. Select the start point and end point of the line as P1 and P2, respectively. This defines the direction of the extended line.

Enter 2 as Horz Dist then press the Tab key on your keyboard. A sample screen is displayed at the end of this article.

Press the Store button to create the Traverse Point.

Click the “Disable Data Input Panel” tool on the toolbar at the top to close the Traverse dialog.

Then select the Line Feature and use Edit/Insert Node to add the position of the Traverse point as a node of the line.

You can hide or delete the Points and Traverse Topics afterwards.

3. Use CoGo/Scale

Use this method if you know the ratio of the new line length to the original line length.

First create a Point Feature Topic.

Select the Line Feature and use Utilities/Disconnect Line to Points and select the Point Feature Topic as the topic for the two points.

Do not mark the checkbox for “Delete the original Feature”.

Select CoGo – Translate/Rotate/Scale.

Select the Line as the target Feature.

Click the Scale Tab in the dialog.

Select the start point of the line as the Fixed Point.

Enter the desired scale and press the TAB key on your keyboard.

Unmark the “Del original data” checkbox.

Click the Store button to store the node.

Click the “Disable Data Input Panel” tool on the toolbar at the top to close the Traverse dialog.

Double-click the T_R_S topic on the left side to select the new line segment.

Select the original Line Topic and use Edit/Paste to Topic to paste the new line segment to that topic.

You can hide or delete the Points and T_R_S Topics afterwards.

CoGo Traverse

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