Archive For The “QGIS” Category

Ubuntu GIS from Scratch: Step Six – QGIS

Welcome to Step Six in our exploration of open source GIS using Ubuntu. In the previous installments, we uploaded some spatial data into a PostGIS database, and experimented with spatial SQL. Finally, we’re ready to install QGIS, the most popular open source GIS desktop available. QGIS is a lot like ESRI’s ArcMap, in that it [...]

Read more »

Python Disabled in QGIS?

This afternoon, I opened QGIS, and was greeted with a strange error message: Couldn’t load PyQGIS. Python support will be disabled. Traceback (most recent call last): File “”, line 1, in RuntimeError: the PyQt4.QtCore module is version 1 but the qgis.core module requires version -1 QGIS will still open if Python support is disabled, but [...]

Read more »

Getting to Know QGIS

Slashgeo linked to an incredible web-based QGIS tutorial last week.  I’ve been looking through it, and so far it is excellent.  It’s not really designed for total newbies – there are other places to get your very first introduction to a desktop GIS.  Instead, this tutorial seems to be aimed at those who are familiar [...]

Read more »

Catching Bad Characters

When loading data into a PostGIS database using shp2pgsql, have you ever gotten this cryptic error? Unable to convert data value to UTF-8 (iconv reports “Invalid or incomplete multibyte or wide character”). Current encoding is “UTF-8″. Try “LATIN1″ (Western European), or one of the values described at http://www.postgresql.org/docs/current/static/multibyte.html. This means that there is an invalid [...]

Read more »

A Difference of Projections

If you divide your time between ArcGIS and QGIS, you may have noticed that they don’t use the exact same projections.  For Northern Colorado, for example, ArcGIS offers “NAD 1983 HARN StatePlane Colorado North FIPS 0501″, while the best QGIS can do is “NAD83(HARN) / Colorado North”.  When projection information doesn’t agree exactly, I get [...]

Read more »