Coordinate Reference System (CRS) information is often stored in three key formats, including proj.4, EPSG and WKT. Learn more about the ways that coordinate reference system data are stored including proj4, well known text (wkt) and EPSG codes.
last updated: 11 Sep 2020
Geographic coordinate systems span the entire globe (e.g. latitude / longitude), while projected coordinate systems are localized to minimize visual distortion in a particular region (e.g. Robinson, UTM, State Plane). Learn more about key differences between projected vs. geographic coordinate reference systems.
last updated: 11 Sep 2020
A coordinate reference system (CRS) defines the translation between a location on the round earth and that same location, on a flattened, 2 dimensional coordinate system. Learn how to explore and reproject data into geographic and projected CRS in Python.
last updated: 11 Sep 2020
In this lesson you learn the steps to create a map in R using ggplot.
last updated: 03 Sep 2019
You can use R as a GIS. Learn how to create a map in R using ggplot in this R maps tutorial.
last updated: 03 Sep 2019
In this lesson you break down the steps required to create a custom legend for spatial data in R. You learn about creating unique symbols per category, customizing colors and placing your legend outside of the plot using the xpd argument combined with x,y placement and margin settings.
last updated: 30 Mar 2020
In this lesson you learn how to reproject a vector dataset using the spTransform() function in R.
last updated: 03 Sep 2019
This lesson discusses ways that coordinate reference system data are stored including proj4, well known text (wkt) and EPSG codes.
last updated: 13 Mar 2020
Geographic coordinate reference systems are often used to make maps of the world. Projected coordinate reference systems are use to optimize spatial analysis for a region. Learn about WGS84 and UTM Coordinate Reference Systems as used in R.
last updated: 13 Mar 2020
Coordinate reference systems are used to convert locations on the earth which is round, to a two dimensional (flat) map. Learn about the differences between coordinate reference systems.
last updated: 03 Sep 2019
This lesson reviews the core files that are required to use a shapefile including: shp, shx and dbf. It also covers the .prj format which is used to define the coordinate reference system (CRS) of the data.
last updated: 03 Sep 2019
This lesson introduces what vector data are and how to open vector data stored in shapefile format in R.
last updated: 30 Mar 2020