Examples of grid corrgrams

Package overview

The corrgram package provides functions for creating corrgrams using three different graphics systems, base, grid, and lattice.

Base R graphics + single function corrgram() for dataframes or matrices. + Enables most features found in the paper by @friendly2002corrgrams. - No automatic legend. - Not easily combined with other graphics.

lattice graphics + Separate panel functions for lattice::levelplot() for dataframes and lattice::splom() for correlation matrices. + Enables automatic legend. + Enables corrgrams conditioned on other variables. + Can be combined with other lattice graphics for complex figures. - Not feature complete compared to base R.

grid graphics + single function corrgram2() for either dataframes or correlation matrices. + Enables automatic legend. + Can be combined with other grid graphics for complex figures. - Not feature complete compared to base R. + Faster than base R when evaluated inside Positron.

This vignette

This vignette demonstrates how to create corrgrams using grid graphics with the corrgram2() function and a variety of panel functions for visualizing correlations in different ways.

Grid Panels for corrgram2

This vignette demonstrates the use of grid-based panels in corrgram2, which provide flexible and modern correlation matrix visualizations.

Correlation matrix corrgram in grid

The vote dataset contains roll call voting records for US Senators. Here we show a grid-based correlation plot with absolute correlations, ordering, and a legend.

corrgram2(vote, abs = TRUE, order = TRUE, legend = TRUE, title = "vote data")

Dataframe corrgram in grid

The auto dataset contains various automobile attributes. We select a subset of numeric variables and display a grid-based correlation plot using the fill panel.

vars6 <- setdiff(colnames(auto), c("Model", "Origin"))
corrgram2(auto[, vars6], 
          lower.panel = grid_panel.shade, upper.panel=grid_panel.pie,
          title = "auto data", legend = TRUE)