OSGeo Discourse

[Qgis-us-user] Heat Maps

Michael_Hundt May 21, 2021, 5:55pm 1

Hello,

I am trying to create a heat map indicating how many cats we have detected at specific locations on our game cameras.

The 10 cameras have detected from one cat to as many as 28 cats.

How do I format this information in a CSV file? Or is another way to display and manipulate the heat map.

Currently, I have a Google map of the camera grid on one layer, and on a 2nd layer indicated the GPS location of each camera.

DO you need more information to help you help me?

Best Regards
Mike

Karsten May 21, 2021, 6:44pm 2

Hi Michael,

you could convert the raster data to point vector layers (not sure how big your data is and why you don’t have have camera location as vector …).
and could work the point layer directly…

But to your question: a simple csv file to load into QGIS could look like this:

id,x_coordinate,y_coordinate,cat species
101,-34.636854,48.468562 ,cat1
102,-122.350595,45.581067,cat2
103,-122.448685,45.582003,cat3
104,-122.320488,45.583881,cat2

To load use the import csv button. see e.g. here https://www.qgistutorials.com/en/docs/3/importing_spreadsheets_csv.html

Note that the process would then create one point for each cat sighting at each camera (so that would duplicate points if there was more then one sighting at a location/ camera).

A way to avoid that would be to load a csv file of all camera location e.g. like this

camera locations table

camera_id,x_coordinate,y_coordinate
1,-34.636854,48.468562
2,-122.350595,45.581067
3,-122.448685,45.582003
4,-122.320488,45.583881

and a cat sightings table
sighting_id,camera_idx_coordinate,y_coordinate,cat species
101,1,-34.636854,48.468562 ,cat1
102,1,-122.350595,45.581067,cat2
103,2,-122.448685,45.582003,cat3
104,3,-122.320488,45.583881,cat2

and then join a second csv (or excel spread sheet) to the camera_id field
see tutorial here http://www.qgistutorials.com/en/docs/performing_table_joins.html
or simpler explanation here https://guides.library.duke.edu/QGIS/Joins

You could then also generate a number of sightings to each camera location to create a heat map…

Let me know that makes sense and help you out

Cheers
Karsten

From: Qgis-us-user [mailto:qgis-us-user-bounces@lists.osgeo.org] On Behalf Of Michael Hundt
Sent: Friday, May 21, 2021 10:56
To: qgis-us-user@lists.osgeo.org
Subject: [Qgis-us-user] Heat Maps

Hello,

I am trying to create a heat map indicating how many cats we have detected at specific locations on our game cameras.

The 10 cameras have detected from one cat to as many as 28 cats.

How do I format this information in a CSV file? Or is another way to display and manipulate the heat map.

Currently, I have a Google map of the camera grid on one layer, and on a 2nd layer indicated the GPS location of each camera.

DO you need more information to help you help me?

Best Regards
Mike

Michael_Williams May 21, 2021, 6:47pm 3

Karsten,

Great explanation. Guess it just goes to show; with GIS, there’s usually more than one way to “skin a cat”.

···

Michael Williams
On 5/21/2021 1:44 PM, karsten wrote:

Hi Michael,

you could convert the raster data to point vector layers (not sure how big your data is and why you don’t have have camera location as vector …).
and could work the point layer directly…

But to your question: a simple csv file to load into QGIS could look like this:

id,x_coordinate,y_coordinate,cat species
101,-34.636854,48.468562 ,cat1
102,-122.350595,45.581067,cat2
103,-122.448685,45.582003,cat3
104,-122.320488,45.583881,cat2

To load use the import csv button. see e.g. here https://www.qgistutorials.com/en/docs/3/importing_spreadsheets_csv.html

Note that the process would then create one point for each cat sighting at each camera (so that would duplicate points if there was more then one sighting at a location/ camera).

A way to avoid that would be to load a csv file of all camera location e.g. like this

camera locations table

camera_id,x_coordinate,y_coordinate
1,-34.636854,48.468562
2,-122.350595,45.581067
3,-122.448685,45.582003
4,-122.320488,45.583881

and a cat sightings table
sighting_id,camera_idx_coordinate,y_coordinate,cat species
101,1,-34.636854,48.468562 ,cat1
102,1,-122.350595,45.581067,cat2
103,2,-122.448685,45.582003,cat3
104,3,-122.320488,45.583881,cat2

and then join a second csv (or excel spread sheet) to the camera_id field
see tutorial here http://www.qgistutorials.com/en/docs/performing_table_joins.html
or simpler explanation here https://guides.library.duke.edu/QGIS/Joins

You could then also generate a number of sightings to each camera location to create a heat map…

Let me know that makes sense and help you out

Cheers
Karsten

From: Qgis-us-user [mailto:qgis-us-user-bounces@lists.osgeo.org] On Behalf Of Michael Hundt
Sent: Friday, May 21, 2021 10:56
To: qgis-us-user@lists.osgeo.org
Subject: [Qgis-us-user] Heat Maps

Hello,

I am trying to create a heat map indicating how many cats we have detected at specific locations on our game cameras.

The 10 cameras have detected from one cat to as many as 28 cats.

How do I format this information in a CSV file? Or is another way to display and manipulate the heat map.

Currently, I have a Google map of the camera grid on one layer, and on a 2nd layer indicated the GPS location of each camera.

DO you need more information to help you help me?

Best Regards
Mike
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