5

I'm trying to create 5 maps in composer showing the same layer features but different extents of a map (attached an image to give everyone an example). I've opted to use atlas to save me manually creating 5 maps... but I have hit a barrier.

I think where I am going wrong is that I am trying to create an atlas based off a point layer (which is my coverage layer) so it is creating individual maps (about 60 +) for the points displayed.

However... I would like atlas to generate 5 maps for the different geographical extents that cover those points?

I right in thinking that I'll have to go and create a polygon shapefile that creates say a bounding box around 5 different areas to contain the points of interest? & then select this as my coverage layer when generating an atlas?

Does anyone know a way to achieve what I am trying to do? Any views or general help would be great.

what I would like to do

2
  • do you want just a detailed map for each point cluster or zoom to each point cluster with atlas function and don't care about the overview map?
    – LaughU
    Jun 16, 2017 at 6:40
  • a detailed map for each point cluster. So taking the image I provided above ^ as my main work area, I then open map composer and generate an atlas, creating 5 individual maps for the cluster points.
    – Beaver
    Jun 16, 2017 at 6:47

4 Answers 4

7

You assume correctly, that you need to have one feature for each map in thecovrage file. based on your image I would advise you to create a polygon layer, with 5 polygons, which represents the individual areas of interest. This layer would be used as the coverage layer. You can hide this layer so it does not show on the map.

If you have a point layer for each region, you could go to processing -> QGIS geoalgorithms -> vector general tools -> Polygon from layer extent. With this tool, you would create your polygons, merge them into one file and use it as a coverage layer. With this approach, which can also be a batch process, you could create reproducible results

1
  • 1
    thank you @LaughU I did not know about geoalgorithms so when I go back to mapping I will try this out.
    – Beaver
    Jun 16, 2017 at 7:05
3

A solution that i often use for this kind of task is to use a point layer as the coverage layer.

This point layer (let's say 'Atlas features') contains one point per area of interest and the attribute table is fill with some specific data like height, width, scale, orientation, name,... This value can then be used as parameters in the atlas generator to get output that exactly fit to the desired size, scale,...

Very useful when your atlas need to have different page format or scale.

1

If the points you want in each map share a common attribute (Group or City) you can use the tool: Minimum bounding geometry to quickly create the bounding box layer needed for each area.

Then in atlas, you choose that bounding layer as your Hidden coverage layer

1

My recommendation is to use the "Create a Virtual Layer" option. Thus, when inserting, updating or deleting points, it will automatically be updated. Example:

"SELECT st_envelope(ST_Union(geometry)) AS geometry
FROM Fotos group by cd_setor"

Finally, you use this virtual layer as a parameter for Atlas.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge that you have read and understand our privacy policy and code of conduct.

Not the answer you're looking for? Browse other questions tagged or ask your own question.