Well, I confess, I'm new to GIS applications and I do not know a lot about projections.<br>I understand I have to tell MapServer what is the projection of each layer I use in the mapfile, but using ogrinfo on my shapefiles tells me that :<br>
<br>Layer name: pop_density<br>Geometry: Point<br>Feature Count: 249937<br>Extent: (-180.000000, -56.000000) - (179.750000, 83.500000)<br><b>Layer SRS WKT:<br>(unknown)</b><br>latitude: Real (24.15)<br>longitude: Real (24.15)<br>
densite: Real (24.15)<br><br>I generated this shapefile from a CSV file with 3 columns : latitude, longitude, density_value.<br>Did I have to define a projection then ? How do I do that ?<br><br>Best regards,<br><br>Faldor<br>
<br><div class="gmail_quote">2008/5/27 Fawcett, David <<a href="mailto:David.Fawcett@state.mn.us">David.Fawcett@state.mn.us</a>>:<br><blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">
<div>
<div><span><font color="#0000ff" face="Arial" size="2">Have
you defined an output projection for your map and input projections for each of
your layers? It is likely that MapServer needs to know what the input
projection/SRS is before it can translate to different
units.</font></span></div>
<div><span><font color="#0000ff" face="Arial" size="2"></font></span> </div><font color="#888888">
<div><span><font color="#0000ff" face="Arial" size="2">David.</font></span></div></font><div><div></div><div class="Wj3C7c">
<blockquote style="margin-right: 0px;">
<div></div>
<div dir="ltr" align="left" lang="en-us"><font face="Tahoma" size="2">-----Original Message-----<br><b>From:</b> Pierre-Benoit
Besse [mailto:<a href="mailto:besse.pb@gmail.com" target="_blank">besse.pb@gmail.com</a>] <br><b>Sent:</b> Tuesday, May 27, 2008 11:26
AM<br><b>To:</b> Fawcett, David<br><b>Cc:</b> Ritesh Ambastha;
<a href="mailto:mapserver-users@lists.osgeo.org" target="_blank">mapserver-users@lists.osgeo.org</a><br><b>Subject:</b> Re: [MAPSERVER-USERS]
Displaying population density with Mapserver<br><br></font></div>Ha, well, I
prefer that :) I would need a lot of layer definitions to obtain something
ok...<br><br>But I just tried the "ground units" stuff, I tried with a 50
kilometers wide square and it drew squares the size of ASIA !! oO<br>I had to
define a 1 feet wide square to obtain something more or less ok...<br>Does
anybody know why ?<br><br>Aside from that It seems to work, thank you
!<br><br>I will try the scalesymbol stuff tomorrow.<br><br>Regards<br><br><br>
<div class="gmail_quote">2008/5/27 Fawcett, David <<a href="mailto:David.Fawcett@state.mn.us" target="_blank">David.Fawcett@state.mn.us</a>>:<br>
<blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">Before
you create lots of different layers to simulate symbol scaling,<br>you may
want to try something else. It has been a long time since I<br>have
played with scaled symbols, but give it a try.<br><br>You should be able to
scale the symbols by setting a SYMBOLSCALE in the<br>LAYER object.
This is the scale at which you want the symbol to appear<br>at the
SIZE stated in the map file.<br><br>You may want to modify STYLE MAXSIZE if
you think that you will want<br>your symbols to be larger than 50
pixels.<br><br>Another completely different approach that just came to my
mind would be<br>to use ground units (e.g. meters) to set the size of your
symbol. To do<br>this, set LAYER SIZEUNITS to meters. Calculate
the size of a symbol in<br>meters on the ground that will touch adjacent
symbols, or give you the<br>desired amount of space between the symbols.
That way, the symbols<br>should scale consistently.<br><br>David.<br>
<div><br>-----Original Message-----<br>From: <a href="mailto:mapserver-users-bounces@lists.osgeo.org" target="_blank">mapserver-users-bounces@lists.osgeo.org</a><br></div>
<div>
<div></div>
<div>[mailto:<a href="mailto:mapserver-users-bounces@lists.osgeo.org" target="_blank">mapserver-users-bounces@lists.osgeo.org</a>]
On Behalf Of Ritesh<br>Ambastha<br>Sent: Tuesday, May 27, 2008 10:16
AM<br>To: <a href="mailto:mapserver-users@lists.osgeo.org" target="_blank">mapserver-users@lists.osgeo.org</a><br>Subject:
Re: [MAPSERVER-USERS] Displaying population density
with<br>Mapserver<br><br><br><br>Dear Faldor,<br><br>Robert is absolutely
right. You will have to make different LAYERS for<br>the same POINT layer.
But, define MAX/MINSCALE for each Layer. Change<br>STYLE -> SIZE values
in each of the layer. You are done !!<br><br>Cheers
!<br>Ambastha<br><br><br>Faldor wrote:<br>><br>> Yes, but I need them
to adapt for different extents.<br>><br>> For example, When I zoom out
enough to see the world, I need them 1<br>> pixel wide (it's ugly
otherwise), but when I zoom in I will need then<br>> 2 or 5 or even 30
pixels wide to cover all space.<br>><br>> 2008/5/27 Ritesh Ambastha
<<a href="mailto:group.ritesh@gmail.com" target="_blank">group.ritesh@gmail.com</a>>:<br>><br>>><br>>>
Dear Faldor,<br>>><br>>> <snip>What I need is to have the
points grow to cover all space<br>>> available when I zoom
in.</snip><br>>><br>>> Do you mean that the size of points
should grow? It can be done<br>>> easily by setting proper SIZE in the
STYLE tag.<br>>><br>>><br>>> Regards,<br>>>
Ambastha<br>>><br>>><br>>><br>>> Faldor
wrote:<br>>> ><br>>> > Hi,<br>>> ><br>>>
> Sorry for my first empty message.<br>>> ><br>>> > My
problem is, I need to display population density with
Mapserver.<br><br>>> > The data comes from GPWv3 and has a
resolution of 15'. I converted<br>>> > it to a POINT Shapefile
using ogr2ogr.<br>>> ><br>>> > At first when I display it
on a world map it shows nicely. But when<br><br>>> > I<br>>>
zoom<br>>> > in it begins to show separated points for each value
in the<br>>> > shapefile. What I need is to have the points grow to
cover all<br>>> > space available<br>>> when<br>>>
I<br>>> > zoom in.<br>>> ><br>>> > Is there any
mean to do it with Mapserver ? I did not find it in<br>>> > the
mapfile reference.<br>>> ><br>>> > I don't know if I
explained it well (I'm not english speaking). If<br>>> >
you<br>>> do<br>>> > not understand something, please
ask.<br>>> ><br>>> > Cordialy,<br>>>
><br>>> > Faldor<br>>> ><br>>> ><br>>>
><br>>><br>>> --<br>>> View this message in
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