Contour Plots in ggplot2
How to make Contour Plots in ggplot2 with Plotly.
New to Plotly?
Plotly is a free and open-source graphing library for R. We recommend you read our Getting Started guide for the latest installation or upgrade instructions, then move on to our Plotly Fundamentals tutorials or dive straight in to some Basic Charts tutorials.
geom_contour produces a similar output to
geom_density_2d, except it uses a third variable for the values rather than frequency. The volcano dataset comes pre-loaded on R.
library(plotly) library(reshape2) df <- melt(volcano) p <- ggplot(df, aes(Var1, Var2, z= value)) + geom_contour() + scale_fill_distiller(palette = "Spectral", direction = -1) ggplotly(p)
See here for a list of colour palettes that come with the brewer (discrete) and distiller (continuous) packages.
library(plotly) library(reshape2) df <- melt(volcano) p <- ggplot(df, aes(Var1, Var2, z= value, colour=stat(level))) + geom_contour() + scale_colour_distiller(palette = "YlGn", direction = 1) ggplotly(p)
It's possible to colour in each of the layers, by changing
stat_contour as below. As the edges of the graph indicate, filled contour plots only work when each layer is an enclosed shape rather than an open line; a geom more suited to this functionality would be
library(plotly) library(reshape2) df <- melt(volcano) p <- ggplot(df, aes(Var1, Var2, z= value)) + stat_contour(geom="polygon",aes(fill=stat(level))) + scale_fill_distiller(palette = "Spectral", direction = -1) ggplotly(p)
What About Dash?
Learn about how to install Dash for R at https://dashr.plot.ly/installation.
Everywhere in this page that you see
fig, you can display the same figure in a Dash for R application by passing it to the
figure argument of the
Graph component from the built-in
dashCoreComponents package like this:
library(plotly) fig <- plot_ly() # fig <- fig %>% add_trace( ... ) # fig <- fig %>% layout( ... ) library(dash) library(dashCoreComponents) library(dashHtmlComponents) app <- Dash$new() app$layout( htmlDiv( list( dccGraph(figure=fig) ) ) ) app$run_server(debug=TRUE, dev_tools_hot_reload=FALSE)