Pragmatic Forums | Posts in forum 'Desktop GIS'

License for world borders shapefile posted by Chris Mutel @ Mon, 23 Nov 2009 13:19:48 +0000

Chris Mutel — Mon, 23 Nov 2009 13:19:48 +0000

The world borders shapefile you provide on the desktopgisbook website is better than the publicly-available datasets I have seen elsewhere on the web, but I don’t see any license information about it. I would like to use this as a base dataset for an academic, openly-available creative-commons licensed database (which would also include political organizations and power grids) – could you please tell me what the license of your data is?

Thanks.

GRASS - Problem importing world_borders shape posted by Michael Neubauer @ Mon, 16 Feb 2009 18:23:04 +0000

Michael Neubauer — Mon, 16 Feb 2009 18:23:04 +0000

Thanks for the answer Gary,
works fine now!
But maybe you should change the file on your download-page then, so that not everybody is running in the same problem…

bye
mike

GRASS - Problem importing world_borders shape posted by Gary Sherman @ Mon, 16 Feb 2009 08:20:43 +0000

Gary Sherman — Mon, 16 Feb 2009 08:20:43 +0000

The problem is the shapefile has an attribute named ‘CAT’. GRASS doesn’t seem to like it when it encounters it in the shapefile. The easiest solution is to open the DBF for the shapefile in something like Open Office or Excel and change the field name. You can also edit the field name with a hex editor if you’re careful. Don’t change the length, just the name (e.g. change it to ‘CAR’).

GRASS - Problem importing world_borders shape posted by Michael Neubauer @ Sun, 15 Feb 2009 15:18:32 +0000

Michael Neubauer — Sun, 15 Feb 2009 15:18:32 +0000

Hi Gary,

I follow the instructions to import a shape-file to GRASS and it does not work with your world_borders file!
Importing the cities is no problem, so I guess I suppose my location and everything is ok…

The following error-message appears, when I enter the v.in.ogr prompt for the world_borders

”
A datum name wgs84 (WGS_1984) was specified without transformation parameters.
Note that the GRASS default for wgs84 is towgs84=0.000,0.000,0.000.
Projection of input dataset and current location appear to match.
Proceeding with import…
Layer: world_borders
DBMI-DBF driver error:
Column ‘CAT’ already exists (duplicate name)
Cannot create table.
Error in db_execute_immediate()

ERROR: Cannot create table: create table Weltgrenze2 (cat integer, CAT double precision, FIPS_CNTRY varchar ( 80 ), CNTRY_NAME varchar ( 80 ), AREA double precision, POP_CNTRY double precision)
“

So can you please help me what is the problem? Maybe it is also a problem with the shape-file…?

Thank you very much
Mike

MapWindow GIS / MrSID posted by Richard Bianchi @ Wed, 04 Feb 2009 07:05:56 +0000

Richard Bianchi — Wed, 04 Feb 2009 07:05:56 +0000

THANK YOU! At last I can add a MrSID raster layer! I had done the “Advanced” install, but I hadn’t noticed the gdal16-mrsid plugin in the Libs tree.

Oddly, when I load the SID raster layer, the Projection Selector pops up saying “This layer appears to have no projection specification” and prompts me to select one. The file contains this information, and after loading, it is even shown in the Metadata tab of the Raster Data Properties. But I can live with that.

I guess I need to set my Project Properties CRS to match the SID file projection (and enable ‘on the fly’ CRS transformation), load the raster layer, then load the vector layers (which are WGS 84).

P.S. Sorry for the delay in responding; I thought I had already posted this response last week (just before Firefox crashed).

MapWindow GIS / MrSID posted by Gary Sherman @ Wed, 28 Jan 2009 04:08:20 +0000

Gary Sherman — Wed, 28 Jan 2009 04:08:20 +0000

You have to do an “Advanced” install and choose the desktop and command line packages you want (eg. qgis), then choose gdal16-mrsid plugin from the Libs tree.

MapWindow GIS / MrSID posted by Gary Sherman @ Wed, 28 Jan 2009 03:00:37 +0000

Gary Sherman — Wed, 28 Jan 2009 03:00:37 +0000

I have not used the Windows version (Mac and Linux are my primary platforms). Let me check into it…

MapWindow GIS / MrSID posted by Richard Bianchi @ Tue, 27 Jan 2009 05:33:51 +0000

Richard Bianchi — Tue, 27 Jan 2009 05:33:51 +0000

I’ve installed QGIS 1.0.0-Kore using the OSGeo4W installer on my PC running Windows XP SP3 and I still get “not a supported raster data source” when I attempt to load a SID file. Am I doing something wrong?

MapWindow GIS / MrSID posted by Gary Sherman @ Sat, 24 Jan 2009 00:08:30 +0000

Gary Sherman — Sat, 24 Jan 2009 00:08:30 +0000

The 1.0 release of QGIS (announced today) includes MrSID and ECW support on the Windows platform. For other platforms it is really a packaging/license issue that the QGIS developer team continues to consider.

MapWindow GIS / MrSID posted by Richard Bianchi @ Wed, 21 Jan 2009 15:23:48 +0000

Richard Bianchi — Wed, 21 Jan 2009 15:23:48 +0000

Gary,

First of all thank you for writing Desktop GIS. It is just the kind of book I was looking for and has been very helpful.

One open source desktop application which is curiously missing from the book is MapWindow GIS which can be found at http://www.mapwindow.org/.

I use Quantum GIS to plan and document my geocaching and hiking trips in various nearby Florida parks. The GIS department of local land management government agency makes available on their web site high-quality (as good as 6 inch per pixel!) imagery which is updated every year. This imagery is provided in MrSID format which seems to be fairly common.

Even though MapWindow GIS and QGIS both seem to make use of GDAL, which has the ability to read MrSID format files (at least it does in FWTools 2.2.8), MapWindow v4.6 is able to load SID files while QGIS v0.11 is not.

I don’t appear to be alone in my frustration in QGIS’s lack of support for MrSID format as is evidenced by this tread in the Quantum GIS Forum: http://forum.qgis.org/viewtopic.php?f=5&t=385

Is there some reason why support for this format continues to be left out of QGIS?

area derived world borders posted by Michael Neubauer @ Sat, 06 Dec 2008 16:27:12 +0000

Michael Neubauer — Mon, 08 Dec 2008 23:58:50 +0000

Hello Gary,

I loaded you “world border” shape file in QGIS. Everything works fine.
But when I click with the identifying tool in one of the countries it always gives me a slightly different area derived than what is given in the attribute table:
example:
Area derived: 494.033,400 km2
attribute table: Area: 504782 (without unit, but I guess it is km2 as well)

where does this difference come from?

But thanks a lot for this very good book!

area derived world borders posted by Gary Sherman @ Sun, 07 Dec 2008 01:20:02 +0000

Gary Sherman — Sun, 07 Dec 2008 01:20:29 +0000

There are a couple of reasons for the difference:

1. The AREA attribute may be based on the actual area of the country rather than a “GIS” area. The resolution of the data may not be adequate to capture the true area.

2. If you have projected the data (which it looks like you may have) and are not using an equal area projection the numbers will be a bit different.

Bird Data posted by Gary Sherman @ Fri, 03 Oct 2008 15:45:44 +0000

Gary Sherman — Fri, 03 Oct 2008 15:47:01 +0000

The bird data used in Chapter 3, Working with Vector Data can is now available at: http://desktopgisbook.com/bird_data.

OpenStreetMap posted by Gary Sherman @ Thu, 26 Jun 2008 05:26:28 +0000

Gary Sherman — Thu, 26 Jun 2008 05:26:28 +0000

Can you explain what you mean by:
“There are many tools that you mention that are used by OpenStreetMap.” ?

Most of the desktop GIS applications can’t consume OSM data.

OpenStreetMap posted by Shaun McDonald @ Thu, 22 May 2008 08:56:50 +0000

Shaun McDonald — Thu, 22 May 2008 08:56:50 +0000

I’ve not seen any mention of OpenStreetMap in the contents or the sample chapters of the book. Considing they are now becoming an increasing player in the open source and open geo data markets, it be worth including them. There are many tools that you mention that are used by OpenStreetMap.