Heatmaps in R
How to make a heatmap in R with a matrix. Seven examples of colored and labeled heatmaps with custom colorscales.
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.
library(plotly) fig <- plot_ly(z = volcano, type = "heatmap") fig
m <- matrix(rnorm(9), nrow = 3, ncol = 3) fig <- plot_ly( x = c("a", "b", "c"), y = c("d", "e", "f"), z = m, type = "heatmap" ) fig
Sequential Colorscales: Greys
colors argument understands color brewer palettes (see
RColorBrewer::brewer.pal.info for valid names).
fig <- plot_ly(z = volcano, colors = "Greys", type = "heatmap") fig
colors argument also accepts a color interpolation function like
fig <- plot_ly(z = volcano, colors = colorRamp(c("red", "green")), type = "heatmap") fig
Or, you can do the scaling yourself and use the colorscale attribute directly...
vals <- unique(scales::rescale(c(volcano))) o <- order(vals, decreasing = FALSE) cols <- scales::col_numeric("Blues", domain = NULL)(vals) colz <- setNames(data.frame(vals[o], cols[o]), NULL) fig <- plot_ly(z = volcano, colorscale = colz, type = "heatmap") fig
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)