speed issue

Topics: General Topics
Oct 18, 2006 at 7:08 PM
Hi,

I was wondering how large the shape files used to display the screenshots with the roads on them were?

Also I used a shape file from NAVTEQ of florida's major highways which is 35MB large and it takes about 1 minute to load it and also about a minute to zoom in or out, so I was wondering if there was anyway to speed it up or if the only way to increase performance is to use a smaller shape file.

Thank you for your consideration.
Coordinator
Oct 18, 2006 at 8:33 PM
Hi eruanion -

I'm working on a spatial index for the shapefile which will allow better memory usage and therefore better speed. Is that 35MB free for me to access and experiment with?
Oct 19, 2006 at 5:04 AM
Do NAVTEQ sell shapefiles? How well do they render (look and accuracy wise) Do you have contact/pricing information?

Thanks :)
Oct 19, 2006 at 1:50 PM
Hi codekaizen,

Unfortunately the NAVTEQ data is not free (i wish lol) and the liscensing rights do not allow me to redistribute the data, so i cannot share the 35MB of data for you to experiment, however i believe NAVTEQ allows you to download sample data shape files which will most likely be around that size 30MB so you can test your spatial indexing on those if you want. All you have to do is register with them at no fee and you can download some sample data, usually 2 or 3 states in the united states, around 1GB of data more or less I think. http://www.navteq.com/support/tools.html
you can register here: http://www.navteq.com/developers/navteq.jsp
Since sharpmap takes 1-2 minutes to display 35MB i imagine it will take much longer for 1GB of data, so although im sure your spatial indexing will improve the speed i doubt it will make enough of a difference in the end for 1GB of data, thank you and let me know how your indexing is going, I'll be very ineterested in trying it out once it is completed.

Thanks

Hi dpilcher,

NAVTEQ do sell shape files, one of the format of their data, it is Extremely acurate and as to the looks it depends on your map renderer, sharpmap, Telogis, GeoBase, pepperwhite, Sylvan ect... they all have unique tools to alter the way the data is rendered. You can find all relevant contact information on their web site: http;//www.navteq.com as to rpicing it depends if you wish to use it for private purposes or for redistribution to clients or customers after haveing built an application on top of the data the prices differ you can look at their web site for more information.
Coordinator
Oct 19, 2006 at 3:46 PM
Excellent - the big data is on it's way on a DVD. I've got my hands on the 35 MB shapefile.
Developer
Oct 19, 2006 at 6:27 PM
Here's more big (and free) shapefiles for testing:

NHPN ("Whole U.S. (44 MB)"): http://www.fhwa.dot.gov/planning/nhpn/
National Atlas : http://www.nationalatlas.gov/atlasftp.html

Regards,
Ricardo Stuven.