new postcode searches + changes in searches [closed]

ideology · Post by **ideology** » 14 September 05 7:44 pm

we have finally got our act together and added postcode searches
try entering your postcode in the search box to see how it goes

the reason this took a while was that the search code was getting huge
the one piece of code was doing normal searches, nearby caches, mates, popularity, recommended caches, caches in a state, frequent finders, frequent hiders plus people who recommended this cache also recommend... searches

so, behind the scenes we've split up the code into little modules which are a bit easier to manage.

the downside of this is that there may be some bugs in the rest of the search code. please let us know if you spot any.

the upside of this is that we got the little icons working against searches, so you can see which caches are yours and which ones you've already done

please let us know how it goes!

Damo. · Post by **Damo.** » 14 September 05 8:03 pm

It's working well for the few postcodes I tried out.
One thing I did notice which is the same on geocaching.com and mobile geocaching. A postcode search on 2022 (Bondi Junction) gives results for "Queens Park NSW" (which is next to BJ and shares the postcode), however the results it produces are from a point slightly north of Corowa on the Murray River. Must be an error with the data.

A very useful update. Thanks for all your hard work!

riblit · Post by **riblit** » 14 September 05 8:08 pm

That's good Thanks.

Chwiliwr · Post by **Chwiliwr** » 14 September 05 9:23 pm

How does your system determine a postcode exists and where it might be

I tried 4 in WA and only the Perth 6000 postcode works as expected.

6149 correctly showed that it was Bull Creek WA but the caches displayed are no closer than about 500km away.

6155 showed as a non existent suburb. (It is Willetton just south of Perth and roughly just east of Bull Creek)

&

6330, which is Albany, showed caches from, I think, Lancelin as a base. (They were north of Perth and, of course, Albany is on the South Coast.)

ideology · Post by **ideology** » 14 September 05 9:54 pm

we forget where we got the data from but we are aware that it's a bit dodgy
we will need to develop a way for people to edit the coordinates of postcodes
if anyone has any accurate postcode tables, we would be glad to upload them!

Chwiliwr · Post by **Chwiliwr** » 14 September 05 10:45 pm

I don't have postcodes as such but I do have all the individual localities of WA in a MapInfo GIS layer. I will see if I can join them together by thier postcode and then get a centroid for each postcode that way. I assume that is what you meant. WA only got the whole state defined with bounded localities late last year just before I left the public service job I was in.

I will also see if the contact I used to have in AusPost when I was in that job can help us with a no cost solution but they are required by their regulations to charge for everything they do so it may not be feasable through him. I know that they maintain a GIS layer of all the postcodes and even if we are not allowed to get the boundaries, as that was a commercial dataset last time I had contact, he may be able to wrangle the centroids for me.

Richary · Post by **Richary** » 15 September 05 12:54 am

Searching for 5045 (Glenelg, Adelaide SA) works very well. It lists all the correct caches with the right centrepoint. Only issue I have is all the archived ones are also included. Interesting historically as I have found a lot of them, but of less interest to new cachers perhaps?

2250 Gosford also seems to work well.

riblit · Post by **riblit** » 15 September 05 1:30 am

Postcode 6149 is Rockingham and should be at -32.067332 115.870493 according to the postcode list in GSAK.
That is a fair way from Rockingham Rocks!!!! which is supposed to be in Rockingham.

Out of idle curiousity I just downloaded the latest postcode files from Aust Post. 6149 covers the localities of Bull Creek and Leeming in WA. The Delivery Office is Canning Vale. The file does not list the centroid of the delivery areas so I can't check the location coords.
Rockingham is listed twice in WA 6168 as postcodes 6168 and 6968.

It appears both postcode lists leave a bit to be desired.

Chwiliwr · Post by **Chwiliwr** » 15 September 05 1:54 am

All states have postcodes that are for postal reasons only and do not represent a locality/suburb as such and are generally not for general usage. In WA that is from 6800 upwards. Also you can usually delete anything that does not say Delivery Area in the Category field. It is usually better to get the PC_Book file unless you are trying to store real addresses that mail can be sent to and then you have to use the PC_Full file. I had to redesign a database for names, addresses, etc and try and load these files. In the end we did two validations, one for postal and one for physical locations.

Anyway it didn't work too well and the dept I was working for got the defined boundaries of all the localities/suburbs in WA as a GIS dataset and only used these localities attributes for the physical locations that were being stored. That is how I got the locality/suburb file in the first place as I had to massage it so that each boundary aligned properly with the ones adjacent to it. There was noone else in the govt agencies bothered that they didn't match properly at the time as the whole state wasn't fully covered up to late last year.

When I can get some time I will join the localities with the same postcode attribute and then provide you with the centroid of them so you can at least get WA better.

I have some ideas that may help with the eastern side of Australia if I can't get anything from AusPost itself.

GeoWombats · Post by **GeoWombats** » 15 September 05 6:58 am

I'm in 0810 and the list seems fairly accurate except for one cache that should be Brinkin that seems to have migrated south to Rapid Creek. Not sure where the cut off line is on your map.
Also one cache that I would call Fannie Bay has ended up in Stuart Park but the boundary line would be close so maybe it is on the SP side. Otherwise the Top End ones look pretty good.

riblit · Post by **riblit** » 15 September 05 10:20 am

That would be good Chwiliwr. It appears there are a couple of differing interpretions around.

I had thoughts of comparing the current list against that in GSAK however for some reason the postcode file (POSTC.DBF) is encrypted

and the php bbase functions show the value of the numeric fields as 0. The data are available in human readable form from the search function under Centre Point -> postcode -> search but it will take a while to manually check.

Dooghan · Post by **Dooghan** » 15 September 05 8:36 pm

Just gave your database a try for the postcodes in my local area. First up was Rockhampton's postcode of 4700. It came back as Great Keppel Island. This is right as it has the same postcode as Rockhampton so I don't know what to do about it. Next up 4701 which is North Rockhampton. I got back Limestone Creek which didn't know where the hell that was. So a quick check in oziexplorer told me it was somewhere near Yeppoon, 30 km away from Nth Rocky. Also it's postcode is 4703 not 4701. Something else I found was this

Notice how Your a Dead Man Dooghan is before the Borough and Double Head. Just a small thing. Here is something for Riblit. All of Aust postcodes with coordinates Postcodes

riblit · Post by **riblit** » 15 September 05 9:10 pm

Dooghan wrote:.. Here is something for Riblit. All of Aust postcodes with coordinates Postcodes

The locations are a bit suss, I've been doing a bit of research. It appears there have been various attempts at generating centroids from various bits of data. All slightly different. I'll add those ones to my database and have a look through them. I have been thinking of a collabrative approach to generating a dataset.

Thanks for the link.

Chwiliwr · Post by **Chwiliwr** » 16 September 05 1:55 am

I had a look at the data provided by Dooghan and it would be at least 75% accurate over the Perth Metropolitan area but only about 40% outside of the metro area. There are also numerous entries that shouldn't be there for the type of searching I think you are trying to achieve.

Assuming that the accuracy was at least the same with the other states then it would be a good start point for the metro areas anyway.

I also noticed it is also a locality, postcode, centroid table not a postcode, centroid table.

Riblit, Can I confirm you want centroids for individual postcodes and not localities/suburbs. ie 6149 will give you one centroid not a centroid for Leeming and another one for Bull Creek which are the two localities/suburbs that have 6149.

ideology · Post by **ideology** » 16 September 05 6:55 am

for what it's worth, our current postcode data is at http://geocaching.com.au/stats/statpack/postcodes.csv
if someone can help clean it up, that would be a great help!
perhaps we could split it up by state or something

regarding multiple centroids per postcode, we'll probably need to have some code which says:
- select all centroids for a postcode
- if they vary by over a certain amount, display a dialog box which allows the user to select which centroid
- display caches around the centroid