Re: [sf-bike-planner:0] Digest for sf-bike-planner@googlegroups.com - 1 Message in 1 Topic

2 views
Skip to first unread message

Garlynn Woodsong

unread,
Dec 15, 2009, 12:23:29 PM12/15/09
to sf-bike...@googlegroups.com
Amar-

Quick stab at answering your questions:
    Questions for all the GIS experts out there:
     
    1. qGIS offers a choice of many formats importing data via "Add Layer." I
    noticed one of these is "CSV." Does anybody know details of the csv format
    in gQIS? Would I be able to export my bike graph to CSV and view it in GIS
    that way? I'm imagining csv with rows of [Lat,Lon,Value1,Value2,...] for
    nodes and [StartLat,StartLon,EndLat,EndLon,Distance,Value1,Value2,...] for
    edges.
Yes, you could export a series of x,y values to CSV, and then re-import them using the qGIS equivalent of "Add X,Y Values" by loading them as a CSV file. It should work just fine, as long as there is at the very least a column for Unique ID (maybe called OID and numbered sequentially from either 0 or 1), a column for X, and a column for Y... but the heading structure that you mention should, in theory, work as well -- I'm not entirely familiar with the qGIS data loading mechanism, however, so maybe somebody else can speak to that.
 
    2. Another format qGIS supports is '.sql' file -- I think this is sqllite.
    What would such a file look like and where would it come from? If I have a
    programmed sql file generated using "pgsql2shp" could I read that in
    directly some way? I'm guessing not, have to run it in a PostGIS DB and then
    connect to the DB. Does anybody do this regularly now?
I've always thought of SQL as a query language, not a geographical data format, so... beats me! 
    3. What is GRASS. Do I need it?
No. Not if you already have qGIS. It's the oldest open-source GIS program, and qGIS has a better interface with much the same functionality, as I understand it...
 
    thanks
     
    Amar

     

--

You received this message because you are subscribed to the Google Groups "sf-bike-planner" group.
To post to this group, send email to sf-bike...@googlegroups.com.
To unsubscribe from this group, send email to sf-bike-plann...@googlegroups.com.
For more options, visit this group at http://groups.google.com/group/sf-bike-planner?hl=en.



--
               O
       O           ...let's go do
   O                        something
 O                              i n t e r e s t i n g
O                 .garlynn.g.woodsong.
...............................................................
http://undergroundscience.blogspot.com
o  o  o  o  o  o  o  o  o  o  o  o  o  o  o  o  o  o
Reply all
Reply to author
Forward
0 new messages