Hello Stephen, Daniel and all. Thank you very much for your candid comments and taking out time to respond to the issues I raised.
Even though it probably appears so, I am not just copying random pieces of code. The workshop builds on previous versions and I have tried to follow it as closely as possible and only make modifications based on the data I am working with. I am not working with OSM data, instead I started with shapefiles loaded as a table (eastlegon) into a postgis database (which I named routing). My data is also entirely in ESPG 4326 and I am working from a windows machine but was able to install pgrouting easily using the installer at http://winnie.postgis.net/download/pg2/buildbot/postgis-bundle-pg92x32-setup-2.1.1-1.exeto my already existing PostgreSQL database. I loaded the data, added the additional columns, ran the topology function, added indices, ran queries using the algorithms (bearing in mind my table name) and I got results similar to the workshop. All of this I fully understand and I've done it more than once just to be sure I am not making any mistakes so much that I can almost do it in my sleep. However, if you advise that I start again from scratch, create a database 'pgrouting-workshop', and table 'ways' instead of my existing setup, I will! Everything works fine till I get to the wrappers part of the workshop. The one with link Daniel shared. I must admit, I've tried to understand the code, and I'm still working on it, and that's why it appears I simply copy it. Two simple questions I now have are: 1) Is there any existing resource that explains (as straightforward as possible) the basics of how to write a wrapper from scratch for a beginner like me? 2) Do I actually need to write custom wrappers (based on my dataset) to get my application to work? All I'm simply trying to do is create a simple application that allows users to set a start and end point, calculate route using at least dijkstra algorithm and display the results as a new layer, all in a web browser. If I do, how best do you advise I go about it. If not, how best can I build on the workshop to achieve my goal. Thanks once again for your time. Without you guys and the work you've done I would not even know where to get started. I really appreciate. Regards, Emmanuel Adegboye On Jan 10, 2014 1:18 AM, "Daniel Kastl" <[email protected]> wrote: > >>> I tried running thr pgr_fromAtoB wrapper function in pgAdmin and I >>> initially get an error: >>> >>> ERROR: relation "vertices_tmp" does not exist >>> SQL state: 42P01 >>> Context: PL/pgSQL function pgr_fromatob(character varying,double >>> precision,double precision,double precision,double precision) line >>> 11 at EXECUTE statement >>> >>> >> I think Daniel will have to answer this. pgr_fromatob() must be a wrapper >> as that is part of the tutorial because it is not part of the pgrouting >> release. >> >> > This is the function: > http://workshop.pgrouting.org/chapters/wrapper.html#route-between-lat-lon-points-and-return-ordered-geometry-with-heading > > As Steve mentioned, you will not be successful to copy pieces of code > (randomly) without understanding what actually is going on there. > > The workshop really tries to explain everything, and I don't think it > makes sense to just copy the text from the link above. It should be all > explained. If you're missing some information, or something is unclear, > then feel free to ask. > > Daniel > > > > > > > > -- > Georepublic UG & Georepublic Japan > eMail: [email protected] > Web: http://georepublic.de > > _______________________________________________ > postgis-users mailing list > [email protected] > http://lists.osgeo.org/cgi-bin/mailman/listinfo/postgis-users >
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