[Qgis-user] Dot Density Symbology

[Shinoto, PD Dr. Maria]

Oops, this was in my Spam folder. It seems that this is the solution to the problem. Thanks a lot!
Maria


Am 2023/07/28 um 08:04 schrieb Alexandre Neto <alexandre.neto at qcooperative.net>:

Hello Hugh,

https://docs.qgis.org/3.28/en/docs/user_manual/style_library/symbol_selector.html#random-marker-fill

Check the random marker fill. I believe it's what you are looking for. As you can see in the docs, you can decide how many points you want to insert inside the polygon. This option can be derived of each feature attributes

Best regards,

Alexandre Neto
User Support
www.qcooperative.net<http://www.qcooperative.net/>

A quinta, 27/07/2023, 18:27, C Hamilton via QGIS-User <qgis-user at lists.osgeo.org<mailto:qgis-user at lists.osgeo.org>> escreveu:
This may not be an answer to your question, but the Density Analysis plugin (https://plugins.qgis.org/plugins/densityanalysis/) will create a uniform set of polygons over an area of interest with a NUMPOINTS attribute of the number of points are contained within the polygon. The NUMPOINTS value can be weighted using some other attribute. It will automatically style the density map as well from a given color ramp.

Calvin

On Wed, Jul 26, 2023 at 8:06 PM Shinoto, PD Dr. Maria via QGIS-User <qgis-user at lists.osgeo.org<mailto:qgis-user at lists.osgeo.org>> wrote:
Hi,

I have a similar research problem, and the dots seem to be a wonderful solution.

So, this email does not give any assistance re the original question, just an answer to the question below:

Am 2023/07/27 um 03:45 schrieb chris hermansen via QGIS-User <qgis-user at lists.osgeo.org<mailto:qgis-user at lists.osgeo.org>>:

Here's (apologies for the closed source link) an example of the type of map/symbology I'm trying to describe.https://www.arcgis.com/apps/mapviewer/index.html?webmap=30d2e10d4d694b3eb4dc4d2e58dbb5a5

Thanks for any suggestions!

What about just shading the polygons using a gray scale?

Given that your polygons should generate a uniform density of dots within the area they bound, I don't see value in generating the dots for symbology.

The polygon area may vary, as it does in my research (distribution of burials in administrative areas). Therefore, a small area always looks underrepresented as compared to a larger area, and vice versa. I have large administrative areas with low densitiy, but they look well populated even with a very light shade of grey.

So I would like to try to find a solution to Chris' problem since the representation with dots is closer to reality than colouring areas. I will report when I found a solution for my use case -- though this may be autumn...

Maria
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