Joe,<br><br>First note that FWtools for Windows is very old and not recommended.<br><br>It is easy to write a python script that cycles through the coordinates and select the census block after applying a filter. We can also cycle through the blocks and get the set of coordinates and then use the OGRGeometry::Contains method to confirm.<br>
<br>The problem here is that there is no straight forward way to use spatial indexes.<br><br>There may be other options, like PostGIS, depending on your exact requirements.<br><br><div class="gmail_quote">On Mon, Mar 19, 2012 at 4:20 AM, Joe McMichael <span dir="ltr"><<a href="mailto:joemcmichael@gmail.com">joemcmichael@gmail.com</a>></span> wrote:<br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><br>Hello GIS folks!<br><br>I have a large number of lat/lon coordinates(120 million) that I would like to know which census block they fall into. Can FWtools be used to crosswalk points to polygons? Maybe you know of a better method?<br>
<br>Thanks in advance for your advice.<span class="HOEnZb"><font color="#888888"><br clear="all"><br>Joe<br>
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<br></blockquote></div><br><br clear="all"><br>-- <br>Best regards,<br>Chaitanya kumar CH.<br><br>+91-9494447584<br>17.2416N 80.1426E<br>