Mean values and standard deviations (SD) can easily be plotted using the ggplot2 package in R. The same approach can also be used to plot the means and confidence intervals. In that case, you plot the lower and upper confidence limits instead of the mean-SD and mean+SD respectively. First, we compute the means and standard…
Functions such as annotate() and geom_text() can be used to annotate a graph in GGPLOT2. This article focuses on the annotate() function which uses data passed in as vectors. The geom_text() function, which uses data frames, is covered in another article. The following example is based on the iris dataset which is available in R….
A scatterplot helps you visualize the relationship between two variables. When there are more than two variables and you would like to visualize the relationship between each variable with every other variable, rather than generating a separate graph for each pair of variables, a scatterplot matrix is a much better approach. A scatterplot matrix presents…
In a previous post, we described how to create a scatterplot plot in R. In the current post we will focus on fitting a regression line to a scatterplot. We will first generate the scatterplot and then fit a linear regression line to the scatterplot. We will look at two ways to do this. Method…
A scatterplot (also known as a correlation plot) is a graph used to visualize the relationship between two variables. When looking at a scatterplot, one is usually interested in the correlation between the two variables. In addition to the type of relationship, a scatterplot shows us if there is a strong or weak correlation, and…