Class Activities on Thursday, Sept. 8
- Discuss Gregory and Ell, “GIS and its role in historical research: an introduction” (on Zotero & Canvas)
- lat/long
- Text Editors
- Data types
- CSVs
- Vectors
After discussing Gregory and Ell’s article (available on both Canvas and Zotero), we will go over the fundamentals of GIS data: latitude and longitude, CSVs (Comma Separated Values data format), Text Editors, and Vectors.
** Tutorial for Loading Vectors in QGIS: https://lincolnmullen.com/projects/spatial-workshop/qgis.html **
- Latitude measures how far north or south a location is on the globe. These lines travel horizontally on the map.
- Longitude measures how far east or west a location is on the globe, and these lines travel vertically on the map. I remember these by thinking that all of these lines are long whereas some latitude lines are short.
- Text editors are simple ways of displaying text with limited manipulation (no bold, italic, or underlines). They display text in lines that will go on for a long time unless you add word-wrapping (a feature that does not break the line of text but wraps it to make it more visible). Text editors are the tools developers use to code. They can be super simple like Notepad or incredibly powerful like Visual Studio Code (my favorite) or Vim (a terminal-based text editor I do not recommend).
- Data Types: “String” (a string of any number or letter), Integers (whole numbers), doubles or Real (decimal numbers), Date (YYYY-MM-dd), Time (HH:MM:SS+nn), DateTime (date and time, YYYY-MM-DD HH:MM:SS+nn)
- CSV is a simple data format with which you are already familiar, even if you do not know it: they basically work like a spreadsheet in which each line is a row of data, and the rows are separated by commas (hence comma-separated value).
- name,age,profession
- Adam,40,data analyst
- Rebecca, 30, teacher
- Other data formats are similar to this, such as tab-separated values (TSVs), etc. We can also expand on the CSV with a CSVT (comma-separated Value Types) value. By default, CSVs are strings, but if we create a file in the same folder, with the same name, but with the extension .csvt that has only one line and the type for each column separated by commas, it will force those columns into that type. For the above example, the file would be
- String, Integer, String
- The one line tells the program that the first column contains strings, the second integers (or whole numbers), and the third a string. This will be important when inputting CSV data into QGIS.
- Vectors are data in Geographic Information Systems (GIS) that are lines on the map (points, lines, multi-lines, polygons) as opposed to being represented as blocks of pixels (rasters, which we will discuss at a later date).
We will go over all of this much more during class.
Homework Due Monday, Sept. 12 (11:59 pm)
Write around 300 words in a blog about what electronic resources exist for your project. Was it easy to find shapefiles? Are there any related projects online? Do you think you can easily make some of your datasets for the project? If so, what
Download and add at least three shapefiles from https://www.naturalearthdata.com/. Post screenshots of the three shapefiles in QGIS to the Blog.
