Spatial heatmap help

[tonypreece]

Hey guys. I'm trying to build a spatial heatmap showing volume of activity for different business locations.

I've set the heatmap tool to use the sales volume column for the heat, my current output is shown below. It's showing retail locations and I've played with different grid sizes/overlaps but it's not giving me what I really want.

What I'm looking for is for each polygon to be different sizes or colours based on volume of sales, something like the second screenshot, but still based on the full UK map.

Is this possible?

[danilang · Accepted solution]

Hi @tonypreece 

I don't know of a way to modify the size of the markers, but you can modify the colours

Here's a modification of my solution to Weekly Challenge #184 Closest Pub to Tobacco Dock. I added a theme to the pub markers based on distance from the dock

  

Giving this

Dan

[tonypreece · Accepted solution]

That's great @danilang. The key was not using the heatmap tool, but going straight from creating points to the report map tool.

The theme options gave me full control over the shape, size and colours of each polygon. Now for the really difficult part, finding which look I like the best!

How I made my happy heatmap

For everyone else finding this post and looking to create a heatmap on a map, here's how I went about it.

I start off with a macro that uses our retail address list and feeds the postcode through an open API to get the location data and a JSON parse tool and filter to keep just the latitude and longitude data before creating spatial points.

Get postcodes - using the Open Postcode Geo API under the Open Government licence*.

Use a formula tool to create a column named URL. The formula is: 'http://api.getthedata.com/postcode/'+[Postcode]

Download tool looks at the [URL] column and doesn't need any further configuration.

JSON parse tool was set to parse the [DownloadData] column created by the download tool.

Now with spatial points created for each location I joined this macro to my list of locations and sales volumes, removing any with no sales using the filter tool (not every location sells the product I was interested in).

The lines down the workflow were failed attempts to do what I needed with the heatmap tool and some data investigations. Importantly, I didn't need the Heatmap tool to create a heatmap!

I used the Report Map tool which did exactly what I needed and rendered it to produce a high quality png output file.

The Report Map tool

I built the heatmap in the Report Map tool and output it with the Render tool.

In the Report Map configuration I increased the map size to 12" x 18" and DPI to 288 for a better quality output. Make sure you set the same DPI in the Render tool so you don't lose image quality.

On the Data tab, click on the #1 incoming connection and set your fields on the right. If you use the grouping field you'll get one map for every group (I have a region column with north/south/east/west for example).

The magic happens in the Layers tab.

Start by adding a Points layer, this shows up as #1. Use the arrows to move it to the top of the list if needed.

Click the + icon to open you're #1 layer and select Style. Here you can choose the shape and size of your point, and even use a customer point shape (any image file).

Then under Theme I chose 'Equal Ranges' and set it to five tiles. This splits your volumetric data (eg sales volumes) into five groups based on volume.

Open up each of the five groups with the '+' icon and set a custom size (default is 10). Give the top group the largest size and increment downwards. You can also use custom colours here if you don't like the default red to blue options, or even give each group a different shape/icon.

I went with a five coloured range and an alternative with the company logo at each point. But here's the fun one I probably won't share with directors!

Enjoy your mapping. Hope this helps someone at some point.

*Open Postcode Geo is derived from the ONS Postcode Directory which is licenced under the Open Government Licence and the Ordnance Survey OpenData Licence. Northern Irish postcodes have been removed as these are covered by a more restrictive licence. You may use the additional fields provided by GetTheData without restriction.

For details of the required attribution statements see the ONS Licences page.