# Creating point C from point A in direction of point B using QGIS?

I have pairs of coordinates which signify the start and end of a transect line. I am trying to adjust the end point such that it is x meters from the starting point.

What I have:

• Coordinates of Points A and B.

What I want to accomplish:

• Create a point C such that it is x meters from point A in the direction of B; or
• Move point B such that it is x meters from point A in the same direction.

Of course I could do this manually since I have just more than a dozen points, but I am trying to be a bit more accurate.

I figured out a solution in QGIS. I think there are several other ways to do it, but hopefully I can help.

1. First you have to define which points are linked together". It means, PointA and PointB need to have the same ID/Attribute (e.g. '1'). All the points are stored in one shapefile. Let's call it POINTS. I cannot give you an exact approach because I don't know how your points are stored.

2. Create a connection (line) between two linked Points (e.g. between all Points containing ID 1 --> PointA to PointB) using either the SAGA module Shapes - Lines - "Convert points to lines" or the QGIS Plugin "Points2One". Call the output LINES

3. Create a buffer with your desired distance (e.g. 1000m using a projected coordinate system). The output will be a polygon surrounding your POINTS with a certain bufferdistance. Call it BUFFER.

4. Create a line as intersection of the POINT to the BUFFER border in the direction of the LINE by using the QGIS Tool "Intersection" (Vector overlay tools - Intersection). Call it INTERSECTION.

5. At the end we have to determine the end of the newly created INTERSECTIONline by a point (POINTC) using the SAGA tool "Convert lines to points" (Shapes - Points) without any Additional Points. Your Result is a file, containing 2 Points for each segment, POINT A and POINT C.

• I was able to do it with the help of plug-ins: "Cadtools" for determining the direction (azimuth) and "Azimuth and Distance Plugin" for drawing them. Anyway, thank you for answering so quickly. I thought I'd come back after an hour. I should have looked sooner. Thank you for this answer and I will definitely try this. Thanks! Jun 15, 2014 at 19:10