It should not be used in isolation of other data nor without a robust conceptual site model.īS8485: 2015 and previous assessment methods (Wilson and Card, 1999, Boyle and Witherington, 2007 and Wilson et al, 2007) require that where the carbon dioxide concentration exceeds 5% consideration is given to increasing a site classification from Characteristic Situation 1 up to Characteristic Situation 2. Ternary plots allow trends in gas composition to be identified and this can help to identify the potential source of the ground gas. This paper explains each of the approaches that are used and the implications that need to be considered when interpreting the data. There are two ways of plotting data in ternary graphs. In most cases the ratios of the three variables are plotted as points on an equilateral triangle (West, 1982). They are also used to assess the flammability of methane and air mixtures (Figure 1) and to assess geological and hydrogeological data.Ī ternary plot is a triangular plot of three variables which must sum to a constant value, e.g. Ternary plots are commonly used to plot ground gas monitoring results (Teasdale et al 20). It also provides advice on using ternary plots to help characterise the ground gas regime and risk where only low concentrations of carbon dioxide and/or methane have been recorded in monitoring wells without elevated flow rates. This paper explains two different approaches that can be used and the implications that need to be considered when interpreting the data. There are various ways of plotting data in ternary graphs. This variation of a Ternary Graph displays three explanatory variables and a fourth response variable, which is visualised in the varying shades of colour:Īnother way to add a fourth variable to a Ternary Graph is to vary the area size of the data points.Ternary plots are commonly used to allow interpretation of ground gas monitoring results. Time-based data can also be displayed on a Ternary Graph by connecting points together with lines or arrows: Small multiples have also been used in this article to visualise and compare different patterns across the Twitter profiles of nine US senators:
#How to read ternary diagram series
You can also see in this graph that multiple data series can be distinguished from one another on the same graph by using different coloured points. Here an analysis was done on Trump’s tweets to see whether they got more retweets, replies or likes, and also have his tweet posts data compared to Obama’s: A good example of this is from FiveThiryEight’s article on The Worst Tweeter In Politics Isn’t Trump. Ternary Graphs can also visualise how data is distributed in a dataset. This makes Ternary Graphs useful in the fields of physical science, such as in geology, physical chemistry, petrology, mineralogy, and metallurgy. Then after when you plot any data points, you’ll see from their positioning on the graph what category the data points fit into. Another use is for classification, which is done by breaking up areas of the graph into different categories like in the examples below: One of them is to find correlations between three variables. There are a few different uses for Ternary Graphs.
#How to read ternary diagram how to
To understand how to read and draw Ternary Graphs, I would recommend you watch these two videos if you’re not familiar with this type of graph: Ternary Graphs visualise the ratios between the three variables, by simply positioning a dot in accordance with its position on each of the three axes (using barycentric coordinates). This triangular-shaped graph is used to plot a dataset with three variables, where the sum of all three adds up to a constant amount. Typically the data is in percentages or in an equivalent decimal form. In this post, I will be exploring the kinds of triangular chart that I’ve come across.Īlso known as a Ternary Plot, Trilinear Graph/Plot, Triangle Graph/Plot, Simplex Plot, De Finetti Diagram, Gibbs Triangle. It’s been awhile since I’ve done one of these posts (the last one being on Area Graph Variations), so I wanted to get back into looking at different chart types.