Both geography and cartography have regained significant popularity in the last two decades as students are increasingly drawn to job opportunities in the geospatial world. In this blog site, I share my own tidbits from geography, GIS, cartography, and planning - fields in which I have spent few years poking around.
Plotting a column of data in a csv file to make a graph is super simple with pandas, the popular Python library. An example code is shown below: The line df = pd.read_csv(".../earthquakes1970-2014.csv") reads the data and stores it as a pandas dataframe object. The next line df.head() allows you to view several rows of … Continue reading Making Simple Graphs with Pandas
Single Band Images Rasterio is a popular open source Python library used for viewing and manipulating rasters. With rasterio, viewing a raster can be done with just a few lines of code, like the example below. Notice, we are using pyplot's imshow method to display the data. The argument src.read(1) means read the first band … Continue reading Displaying Rasters Using Rasterio
Displaying shapefiles in Python using the geopandas and matplotlib libraries is very easy, particularly when using Jupyter notebook. First, import the two libraries into Jupyter notebook, as shown below. import matplotlib.pyplot as plt import geopandas as gpd Next, read the shapefile and convert it into a geopandas dataframe object using the read_file command shown below. … Continue reading Displaying Shapefiles and Attribute Data Using GeoPandas
Traditionally, geography has been a discipline primarily concerned with the location and description of places with the goal of providing people with comprehensive knowledge of the earth as the home of humans. Today, geography still retains this locational and descriptive focus. However, in its modern form, a fundamental goal of the discipline is understanding … Continue reading Geography and Geographic Methods of Problem Solving
Ripley's K and its derivative, the L function, are widely used for detecting clusters over various spatial scales. The figure below is one of my favorites for illustrating the concept of a phenomenon displaying one spatial pattern over long distances, and another pattern over short distances. (Source) The genius of the K function is … Continue reading Ripley K
I just read Geoffrey Jacquez's (2008) paper on “Spatial Cluster Analysis”. Chapter 22 In “The Handbook of Geographic Information Science”, S. Fotheringham and J. Wilson (Eds.). Blackwell Publishing, pages 395-416. I enjoyed reading the paper for the simple fact that it points to a broad range of considerations that should enter into mainstream cluster analysis … Continue reading What else to do in Clusters Analyses?
Thanks to the pioneering efforts of ESRI, it is now relatively easy for GIS users to store their datasets in database software of all sorts. In this post, I present a short overview on storing GIS data in SQL Server Express. SQL Server Express is a free download from Microsoft. After installing it, make sure … Continue reading Loading Vector Data into SQL Express