But wait-- there's more! Earlier in the week I shared Esri's awesome interactive Thanksgiving map and a cool pie chart, but I also wanted to highlight this well-made graphic from Visually. The donut charts are really easy to read, especially with their vibrant-but-not-distracting color scheme. They included the data source and respondent number in unobtrusive… Continue reading Another Thanksgiving Graph!
Thanksgiving Maps!
We're getting into the holiday (finals...) season, so I'm a little short on time for detailed how-to posts right now. Instead, I'll share some quick posts about well made Thanksgiving related maps and graphs! Last year Esri created an interactive map Where does your Thanksgiving dinner come from? that combines some of my favorite things--… Continue reading Thanksgiving Maps!
Maintain your Aspect Ratio!
I spent most of this week at a conference (American Society of Agronomy and Crop Science Society of American joint conference in Baltimore). I learned all sorts of interesting things that are mostly not relevant to this blog, so maybe don't expect a whole lot more conference related content. Overall, the week was a great… Continue reading Maintain your Aspect Ratio!
EPSG Numbers and Coordinate Reference Systems
Over the last month or so I've had a little series about how we describe positions on the globe and how we visualize spherical space on a 2D map. I started with big picture information, like why we care about map projections. Last week began giving more concrete advice for picking a projected or unprojected… Continue reading EPSG Numbers and Coordinate Reference Systems
Selecting a Projection for Spatial Analysis
More map making! When you're first starting a new project and have data files in different projections, you can still view all your data together at once, using something called on-the-fly projection (a common feature of most GIS software). On-the-fly projection displays all your files using your "project CRS" and lets you have map layers… Continue reading Selecting a Projection for Spatial Analysis
New Datum for North America
Before I get off the datum topic, I want to share a little bit about what datum the National Geodetic Survey (NGS) is moving towards. The NGS is a part of NOAA, the National Oceanic and Atmospheric association. If you use weather.gov for anything, you're familiar with the outputs from NOAA. The current official datums… Continue reading New Datum for North America
What’s a datum?
Earlier in the week I gave a quick overview of map projections. Today I'm covering a related topic--datums. North American Datum 1983 is the basis for a lot of common map projections, and World Geodetic System 1984 is the series of latitude and longitude most commonly used on consumer GPS devices. But first, what's a… Continue reading What’s a datum?
Climate change and global yield potential
Yesterday I posted about map projections, and today in class we talked about global trends in agricultural productivity/yield as a motivation for learning about plant breeding. Since productivity is considered on a yield per land area basis, it makes sense to use a map projection that preserves relative size of land masses. Note that I… Continue reading Climate change and global yield potential
What’s a map projection?
At the most basic level, map projections are how we turn the 3D earth surface into something flat. There are polar projections that look at the globe from the top or bottom view, or more common projections that are centered near the equator. Map projections are really easy to overlook, but have large impacts on… Continue reading What’s a map projection?
1915 Ohio Soil Survey
This is only loosely related to other material on this blog, but hey, what's the point of having a blog if you can't write about what you want? Next week I'll get back to the usual data collection, analysis, and mapping content. Earlier this month I spent some time on the NRCS website gathering information… Continue reading 1915 Ohio Soil Survey
Spatially Challenged 