Thank you for your reply, but I'm not quite sure that it answers what I'm looking for- I want to plot postcode information similar to the thread below, I'm just not sure how to go about doing this- I would like to plot each GP practice onto the CCG map, thanks. Though, apologies if I've got this incorrect as I'm brand new to Tableau.
If I understand you correctly then you are trying to create something a little like the picture below, which is an example from a dashboard I created recently? The dots and stars are partner businesses and the colours and shapes represent different types. Tooltips show the details of the business when you hover over a dot or star.
If so, then I'm sorry but I have a nasty feeling you can't do it with your data, or if you can then I would love to know how! I was able to do this by creating a union data set, as you suggest, and then a dual axis map with the area shading on one axis and the points on the other (there are various explanations around to talk you through how to do this, here's one: http://www.evolytics.com/blog/tableau-201-make-dual-axis-map/. But the crucial difference between my example and yours is that my area-shading is done using one of Tableau's standard geographies - in this case, State. I needed to replicate this for the UK with shaded postcode areas, which is not a Tableau standard geography, so I needed to use polygons as you have. But whatever I tried, I was unable to make it work. Creating a dual axis map when one axis has polygon area shading on it seems to just create a scatter plot with the points and shading in roughly the right places (although the shape of the UK appeared somewhat distorted) but with no map features at all.
I wait with interest to find out if there is a way to do it with polygons, although Tableau 10 may solve my particular UK problem, with custom geographies.
The UK postcodes don't have a long and lat - these will be required to plot on a map. Have you looked at downloading (and maybe this is where you got the CCG polygons) the UK postcode polygons for the surgeries? UK Filled Map Geocoding Pack for Tableau - The Information Lab
Alternatively do you have any way to get the long and lat for the surgeries? This may also help: Download UK Postcodes with Latitude and Longitude
Thanks for your answer- I have got the UK postcodes pack and done a VLookup to get the long and lat for the surgeries and about to persevere with it. Thanks for your help.
I am still persevering with this (hoping that now have added postcode data this will work), but will keep you updated!
I've downloaded and sorted the CCG pack from The Information Lab, and I've added my Excel files which have the postcodes and Long/Lat information for the Trusts and GPs. I'm just having real trouble trying to get a relationship (I feel I have to create a Union somewhere but have no idea how to do this) and getting them to show on the CCG map, and have been struggling with this for a while. I'm hoping to have stars represent Trusts and then circles represent the GP surgeries.
I have popped the packaged workbook below. I'm pretty sure this can be done- and is probably reasonably simple but I'm afraid it's just a bit too advanced for me at the moment! Please can anybody help with getting all this information on to one map? Many thanks.