need some help from the mapping gurus here. I use Tableau public for visualization and was trying to play with the pre-delimination shapefiles that someone had previously shared on this thread.
Now Tableau requires the data in a format of pointid, polygonid, subpolygonid, latitude and longitude. and i managed to get that from the .shx after some research on the internet.. but the problem i have is that for some strange reason the latitude and longitude is not really that (snapshot below), but rather a set of numbers which nonetheless gives the recognizable shapes. PolygonID SubPolygonID PointID Longitude Latitude AC_NAME 3 1 1 -12.3218 1.461258 Hulsoor 3 1 2 -12.32 1.461099 Hulsoor 3 1 3 -12.3199 1.461188 Hulsoor 3 1 4 -12.3198 1.461478 Hulsoor 3 1 5 -12.3198 1.46177 Hulsoor 3 1 6 -12.3199 1.461986 Hulsoor How do i convert these number sets like (-12.3218,1.4612) into real latitude and longitude.. i suspect something to do with the Co ordinate reference system. appreciate any help again i am quiet sure this something really basic.. much appreciate any help.. On Sat, Apr 20, 2013 at 4:11 PM, Srinivasan Ramani <[email protected]>wrote: > Let me add that I got through to EC as well... the in charge of the EC's > GIS related IT work, and he put me through to their software vendor.. who > put me through to ... a blank wall... > > > > On Sat, Apr 20, 2013 at 3:29 PM, Shashank <[email protected]>wrote: > >> To close down one line of enquiry, I believe that georeferencing and >> vectorising the PDF maps from the NIC GIS server is pointless. >> >> I've attached my quick-and-dirty attempt here, and have overlaid the >> (pre-delimitation) EC assembly constituency shapefile that was dumped on >> datameet earlier. >> >> At both the georeferencing and vectorisation steps, there's a substantial >> loss of accuracy; at the georeferencing stage because the PDF map and the >> earlier EC data don't match up properly (there are kinks in one boundary >> that aren't duplicated in the other) and at the vectorisation stage the >> actual boundaries in the PDF are very thick, so they could be anywhere >> within a few tens of kilometres of their actual position. In the case of >> Bangalore city particularly, this image is unusable. >> >> Other potential sources I've tried accessing, only to discover that they >> also do not have access to up-to-date AC/PC shapefiles, are the Harvard >> Geospatial Library and CPR. >> >> I'd suggest that the only way of getting a useable version of the data is >> to get the EC to re-release it, ideally under the auspices of the National >> Data Portal. This is obviously easier said than done. >> >> >> On Wednesday, April 17, 2013 7:01:48 PM UTC+5:30, Sajjad Anwar wrote: >> >>> I gave a quick and dirty shot and see the result in the attached image. >>> It's useless. The image is somehow getting flipped when I polygonize. >>> The image is partly useless because of the terrible resolution and >>> colours. >>> >>> I'll take some time out and get to it. Will keep you guys posted if >>> something good happens. >>> >>> Cheers, >>> Sajjad. >>> >>> On Wed, Apr 17, 2013 at 3:18 PM, Karthik Shashidhar >>> <[email protected]> wrote: >>> > Reviving this thread. >>> > >>> > So the maps themselves are available at >>> > http://gisserver1.nic.in/**ecimaps <http://gisserver1.nic.in/ecimaps> >>> > >>> > More specifically the Karnataka Assembly constituency map (pertinent >>> given >>> > the upcoming elections) is available at: >>> > http://gisserver1.nic.in/**ecimaps/ECIPDF/State_ac_map/**KARNATAKA.pdf<http://gisserver1.nic.in/ecimaps/ECIPDF/State_ac_map/KARNATAKA.pdf> >>> > >>> > I think this is a vectorized PDF, so should be able to be converted to >>> shape >>> > files. >>> > >>> > And I assume there is enough expertise on this list to do this >>> conversion. >>> > Can someone do the necessary conversions and post the data? >>> > >>> > Thanks >>> > Karthik >>> > >>> > >>> > On Wednesday, 28 November 2012 12:19:56 UTC+5:30, megha wrote: >>> >> >>> >> Hi everyone, >>> >> >>> >> Can anyone here point me to recent enough shape files for MP/MLA >>> >> constituencies? >>> >> >>> >> Thanks, >>> >> Megha >>> > >>> > -- >>> > For more details about this list >>> > http://datameet.org/**discussions/ <http://datameet.org/discussions/> >>> > --- >>> > You received this message because you are subscribed to the Google >>> Groups >>> > "datameet" group. >>> > To unsubscribe from this group and stop receiving emails from it, send >>> an >>> > email to datameet+u...@**googlegroups.com. >>> > For more options, visit >>> > https://groups.google.com/**groups/opt_out<https://groups.google.com/groups/opt_out>. >>> >>> > >>> > >>> >>> >>> >>> -- >>> Sajjad Anwar | W: http://sajjad.in | T: @geohacker >>> >> -- >> For more details about this list >> http://datameet.org/discussions/ >> --- >> You received this message because you are subscribed to the Google Groups >> "datameet" group. >> To unsubscribe from this group and stop receiving emails from it, send an >> email to [email protected]. >> For more options, visit https://groups.google.com/groups/opt_out. >> >> >> > > > > -- > Best Regards, > Srinivasan V. Ramani , > Senior Assistant Editor, > Economic and Political Weekly , > New Delhi: 110 067 > 09650855669 > > -- > For more details about this list > http://datameet.org/discussions/ > --- > You received this message because you are subscribed to the Google Groups > "datameet" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > For more options, visit https://groups.google.com/groups/opt_out. > > > -- For more details about this list http://datameet.org/discussions/ --- You received this message because you are subscribed to the Google Groups "datameet" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. For more options, visit https://groups.google.com/groups/opt_out.
