Tag Archives: open source

Python Open Labs – Format Strings

Hi

In the 15th session of Python Open Labs, this week we looked at some miscellaneous topics and revision of basic concepts of file reading and string handling from previous sessions. We also briefly looked into format strings / format specifiers for string construction in Python. The relevant slides are available on the Session – 15 folder on the google drive link mentioned below.

All of the course slides and examples are made available on: https://goo.gl/YP0c2E

As always, please keep up with your programming practise, a suggested link for the same is: https://www.hackerrank.com/domains/python/py-introduction

See you next Friday from 1:30 PM – 3:30 PM at DSSC (Room – 215), Lehman Library at Columbia SIPA ! We will be covering some basics about web scraping.

Using OpenStreetMap XML data

osm_xml2

OpenStreetMap is a great resource mostly user created and maintained. The data is free of charge and there are several ways of accessing the data for use in a GIS project.

One of the easiest and quickest ways is to download data from CloudMade in shapefile format, but occasionally not all of the features shown in OpenStreetMap are available in the shapefile download.

An alternative is to download the OSM XML data, open it in QGIS, and if needed, export to shapefile.

To do this, open QGIS and under the Plugins menu, select Manage Plugins and turn on the OpenStreetMap plugin. If it’s not there then you will have to add it from Fetch Python Plugins.

The plugin allows for viewing downloaded OSM XML data, downloading large scale areas directly, and uploading edits you’ve made (account required).

Click on the Load OSM from file icon and navigate to the downloaded OSM XML layer.

Put a check mark next to the fields you want to create (these will only populate if the information is encoded). Keep a check mark next to Use custom renderer if you want to symbolize your data similar to the OSM scheme.

If you need to work with any of the features in shapefile format, right click on a layer and select Save vector layer as, and choose ESRI shapefile from the Format pull down menu if not already selected.

And that’s it!

Intro to GIS using QGIS

On Wednesday we gave our first workshop at the CUMC Health Science Library using the open source QGIS software. It was well attended (19 people) and although there were a few bugs, overall I think it went well.

We’ll give the same workshop again on Friday October 10th from 12-2pm, so for anyone who was not able to attend the first one or were on the wait list will have another chance.

The exercise I use for for the workshop is a shortened, modified version of the FOSS4G2007 “Shuffling Quantum GIS into the Open Source Software Stack” workshop workbook found on the QGIS website under Documentation.

For data the QGIS LiveCD works great, but I use data from Desktop GIS – the book which is almost identical to what is used in the workbook.

There were several good questions, and a few I was unable to answer mostly because I’m more familiar with using ESRI software but I’ll look into the questions and if I can find answers I’ll post them here.

We also received a request to hold a Geoda workshop in the near future which we will look into as a definite possibility.

GIS Intro at the CUMC Health Sciences Library

Thanks to the work of a terrific librarian who works in the CUMC Health Sciences Library, we now are now able to bring the GIS workshops to the Medical Center campus.

To start off with, we will offer the Intro to GIS workshop but will use QGIS, an open source software instead of ArcGIS which is what we use for the majority of our workshops.

Registration won’t open until one week before, but if you are interested in attending you can register from the EDS workshops page.

If you missed the first Intro workshop that took place in EDS, there’s still room in next week’s Friday 9/19 workshop.

EDS GIS Workshops

The fall GIS workshop series is now up, overall we’re looking to introduce a couple new workshops to the schedule including another Google Earth & KML workshop, and a introduction to using Python in ArcGIS.

This year we’re also working on offering GIS workshops using open source software (probably QGIS) at the Health Sciences Library.