Trying to build a map using UK MSOA boundaries without success

[masplin]

I've done this rpeviously using a level up, but trying to map daya at the UK MSOA level

I downlaoded this file form ONS of what I think are boundaries as GeoJSON file MSOA Boundaries ONS 

I then sent that to https://mapshaper.org/  to convert to a TopoJSON file. Previewed looked fine

In power BI I chose map and in map settings custom map, uploaded JSON file and Orthographic.

However instead of getting something that looks like the UK I get this.  Its extremly slow which I was expecting. 

If I click on eventualy I get this sort of thingwhich is looknig good as MSOA21NM is the name I have in my data. 

Question is do I need to name my field the same as this field name in the JSON for it to work? I tried renaming the field in my dataset, but didnt work

Any reason it is rendering liek a globe instead of the country shape?  Not enough resources etc

Any suggestions appreciated. Might just be too much for power BI.

Mike

[masplin]

Thisis the standard shape map.  I've used a topojson file ofr Local authority and orthogrpahic which works fine, but the next level down MSOA therer are 20 x more areas so it is a massive file.  I've tried different files that have the boundaries in clipped detail.  Full files are below

Full Geo JSON 

Full TopoJSON 

Mapshaper seems to allow you to simplify the boundaries so below is 1pct version

1pct TopoJSON 

Be interested if you can get it to work

LA version looks like this

[lbendlin]

Mapshaper doesn't know what the original projection is. Any idea as to what it could be? EPSG:27700  ?

Great Britain

To convert from British National Grid, use projection EPSG:27700. In the long-established, but now less-preferred proj.4 format, the projection is defined as

+proj=tmerc +lat_0=49 +lon_0=-2 +k=0.9996012717 +x_0=400000 +y_0=-100000 +datum=OSGB36 +units=m

[lbendlin]

So yes, you need to convert from BNG to WGS84  (for example with QGIS) and then from GeoJSON to TopoJSON (with Mapshaper).

[masplin]

sorry i have no idea what you mean.  The download from ONS was a Geojson file so assume just needed to convert that. Mapshapper showed the country correctly.  How have you managed to get the correct looking map? I tried all 3 projections and could get what you have?   Can you explain steps as i'm not very tech savvy?  Much appreciated

[lbendlin · Accepted solution]

I'm afraid it's quite a bit more complex than that.

Your GeoJSON file is in BNG projection (EPSG:27700)  which cannot be used in Power BI (neither the format nor the projection). 

First step:  Convert your ONS data from EPSG:27700 to EPSG:4326  .  I used QGIS for that, you can use whatever tool you prefer. Here's a general approach: QGIS – CROPPING AND CONVERTING .SHP FILES TO TOPOJSON FORMAT – Daniels Coding Blog (wordpress.com)

Second step: Convert from GeoJSON to TopoJSON (as you already did, via MapShaper)

Third step:  Have columns in your Power BI data that correspond to the shape attributes in your file.  In your case that would be (at minimum) MSOA21CD. 

Fourth step: load the custom map into the shape map visual, it will automatically display in a suitable (ish) projection.  Mercator is not necessarily the best for the UK locations but it is what it is.

This stuff (especially QGIS) is rather technical, and highly demanding of your computer resources. Bring patience and maybe call a friend.

[masplin]

That brilliant. I'm off on holiday tomorrow so wil lgive it a go when I get back

Thanks again. 

[lbendlin]

I don't think you want to use orthographic projection. try one of the other values.

Which map visual is this?