Using open source software, and free map data, how can I generate a
state map with labelled points generated from a list with latitude and
longitude points? How can I generate this map as a web image map, so
I can link it up with a content page with data about the selected
point? Programming is fine, but the platform needs to be Linux. |
Request for Question Clarification by
mathtalk-ga
on
26 Apr 2004 17:10 PDT
Are you trying to do this for one particular state? All states? Or
solve a general mapping problem?
If you have the outline of state as a bit-mapped graphic, it's not too
hard for a particular map to work out the latitude and longitude
functions (to produce the corresponding graphic coordinates).
But you seem to be mainly concerned with out to generate the overlay
of points on the map as a "web image". One approach would be to
construct a .gif with transparent "color" and the labelled points and
position it on top of the (pre-existing) outline map of the state.
There's another Researcher here who's done a good bit of this sort of
thing. I'll point your Question out to him, but in the meantime you
might Clarify more of what you mean by "free map data". Is this
something you have, or something you would need help in obtaining?
And how much data are you talking about?
regards, mathtalk-ga
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Request for Question Clarification by
j_philipp-ga
on
27 Apr 2004 01:00 PDT
Hello Joshmarcus,
Would PHP be fine for you as scripting language?
Also, do you already have a map image which is copyrighted to you, or
copyright-free -- or do you still need one?
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Clarification of Question by
joshmarcus-ga
on
27 Apr 2004 08:22 PDT
Let me describe a bit more about the problem I am trying to solve. I
am trying to build a website that displays survey information about
low power FM stations in the US. The initial interface will be an
imagemap of the US, and each state will go to an internal page. I'm
less concerned about the generation of the initial US map (and
imagemap). But I want to be able to generate a map of *each* state
with the points of the low power FM stations labelled with their
station name. I will have latitude and longitude for each point in a
database. I want the browser of the page to be able to click the
labelled points (the stations) on the map, and have the information
about the individual stations come up -- in a second page, or perhaps
I'll use javascript to bring up the information on that same page, or
a frame, or whatnot.
I do not have maps (e.g. outline maps) of each state, and so I was
hoping (and assuming) I could get such things from the Census Bureau
or whatnot. It would be nice if I could drop in some extra data into
those maps (like points of major cities) but it's not necessarily
crucial.
I'd prefer to use perl, but if there's a way to do this in PHP I'd be
more than willing to use PHP instead.
Also it is important to note that I want to generate maps *on the fly*
using data in a database -- not make a map *once* and then keep that
map.
Thanks!
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Clarification of Question by
joshmarcus-ga
on
27 Apr 2004 12:29 PDT
I've found some near-free states shapefiles: http://nationalatlas.gov/statesm.html.
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Request for Question Clarification by
mathtalk-ga
on
27 Apr 2004 14:32 PDT
Hi, joshmarcus-ga:
Just to clarify, would you be open to dynamically adding selected
locations (eg. of low power FM stations) to an existing "state map" in
order to obtain the graphic you will display on your Web pages?
regards, mathtalk-ga
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Clarification of Question by
joshmarcus-ga
on
27 Apr 2004 15:28 PDT
Yes, I would be very open to dynamically adding selected labelled
locations to an existing "state map" in order to obtain the graphic
that will be displayed on the web pages.
And then the second piece of the puzzle is how to make sure that the
labels are appropriately "described" by the image map so that the map
can be used as navigation to sites keyed off the locations.
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Request for Question Clarification by
studboy-ga
on
28 Apr 2004 16:01 PDT
Would the following open source GIS map servers work for you?
C/CGI based:
http://mapserver.gis.umn.edu/index.html
Java based:
http://geoserver.sourceforge.net/html/index.php
http://www.geotools.org/index.php?module=articles&func=view
There are other ones at:
http://www.opensourcegis.org/
But after going through every one of them the above three looks most
promising. Let me know if it works for you (also which one you're
most comfortable with: C, Java, ...) and I can post a formal answer.
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Request for Question Clarification by
mathtalk-ga
on
01 May 2004 13:33 PDT
Hi,
While the links offered by studboy-ga are certainly relevant, it seems
to be me a complete solution to the Question will involve three
elements:
- a fixed map image of a state (several of these)
- a dynamically generated overlay image (possibly a GIF with
transparent color) that contains locations of identified low-power FM
stations
- an imagemap defining (say) rectangles that correspond to both the
dynamically selected features as well as an "stock" features for that
state which are deemed worthwhile.
Doing all tasks for all 50 states seems unfeasible, given the limits
of time and price, but a pedagogic approach in which one state is
worked out in detail seems reasonable.
regards, mathtalk-ga
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