Ward names - convert Northern Ireland 2011 codes to 2016

[morkeltry]

2011 census ward codes (WD11CD) look like 95AA01 for Northern Ireland 2016 are standardised like N08000101

[morkeltry]

Maybe converter function from one to t'other?

[chris48s]

There are some important things to note here:

• You mention 2016. The elections that took place in Northern Ireland in 2016 were Northern Ireland Assembly elections. If you're interested in 2016, the relevant unit of electoral geography is Northern Ireland Assembly constituencies. Conveniently, NI Assembly constituencies and Westminster constituencies have the same names and boundaries but each area has 5 representatives in the Assembly as opposed to 1 in Westminster.

You've also mentioned wards. If you need to look at local elections in NI:

• In Northern Ireland local elections, councillors aren't elected to represent wards. The relevant electoral geography for local councillors in Northern Ireland is District Electoral Areas. Any election results you've got from 2014 (or candidate data you've got for upcoming elections in 2019) are going to be at District Electoral Area level.
• Ordnance Survey NI publish the current District Electoral Area boundaries at http://osni-spatial-ni.opendata.arcgis.com/datasets/981a83027c0e4790891baadcfaa359a3_4 as defined in The District Electoral Areas (Northern Ireland) Order 2014
• Inconveniently, that dataset doesn't include the GSS codes ( N10 ) for those areas. Fortunately, you aren't the first person to need them. This will help: https://raw.githubusercontent.com/mysociety/mapit/master/mapit_gb/data/ni-electoral-areas-2015.csv The names of District Electoral Areas are unique within Northern Ireland.
• If you want to try and match up data from 2011 to electoral boundaries after the Local Government Act (Northern Ireland) 2014 which completely restructured local government in NI (related reading: https://en.wikipedia.org/wiki/Reform_of_local_government_in_Northern_Ireland ), there isn't going to be a one-to-one mapping from the old set of wards to new boundaries. You would need to approximate the post-2014 boundaries by using whatever the smallest unit of geography you've got as a building block. See https://github.com/CampaignLab/data-pipeline/issues/20#issuecomment-445575859 for an explanation of building up wards from output areas. The process would be similar.