Perfectly align multiple plots

Question

My goal is a complex plot that combines a scatter plot and 2 plots for density estimates. The problem I am facing is that the density plots are not aligned correctly with the scatter plot due to the lack of labels indicating the density plots and legends of the scatter plot. It can be adjusted by playing arround with plot.margin . However, this would not be the preferred solution, as I would have to adjust it again and again if changes were made to the graphs. Is there a way to position all the graphs so that the actual construction panels line up perfectly?

I tried to keep the code as minimal as possible, but in order to reproduce the problem, there is still quite a lot.

 library(ggplot2) library(gridExtra) df <- data.frame(y = c(rnorm(50, 1, 1), rnorm(50, -1, 1)), x = c(rnorm(50, 1, 1), rnorm(50, -1, 1)), group = factor(c(rep(0, 50), rep(1,50)))) empty <- ggplot() + geom_point(aes(1,1), colour="white") + theme( plot.background = element_blank(), panel.grid.major = element_blank(), panel.grid.minor = element_blank(), panel.border = element_blank(), panel.background = element_blank(), axis.title.x = element_blank(), axis.title.y = element_blank(), axis.text.x = element_blank(), axis.text.y = element_blank(), axis.ticks = element_blank() ) scatter <- ggplot(df, aes(x = x, y = y, color = group)) + geom_point() + theme(legend.position = "bottom") top_plot <- ggplot(df, aes(x = y)) + geom_density(alpha=.5, mapping = aes(fill = group)) + theme(legend.position = "none") + theme(axis.title.y = element_blank(), axis.title.x = element_blank(), axis.text.y=element_blank(), axis.text.x=element_blank(), axis.ticks=element_blank() ) right_plot <- ggplot(df, aes(x = x)) + geom_density(alpha=.5, mapping = aes(fill = group)) + coord_flip() + theme(legend.position = "none") + theme(axis.title.y = element_blank(), axis.title.x = element_blank(), axis.text.y = element_blank(), axis.text.x=element_blank(), axis.ticks=element_blank()) grid.arrange(top_plot, empty, scatter, right_plot, ncol=2, nrow=2, widths=c(4, 1), heights=c(1, 4)) 

Answer 1

Using the answer from Align the ggplot2 graphs vertically to align the graph by adding to the gtable (most likely, this complicates !!)

 library(ggplot2) library(gtable) library(grid) 

Your data and graphics

 set.seed(1) df <- data.frame(y = c(rnorm(50, 1, 1), rnorm(50, -1, 1)), x = c(rnorm(50, 1, 1), rnorm(50, -1, 1)), group = factor(c(rep(0, 50), rep(1,50)))) scatter <- ggplot(df, aes(x = x, y = y, color = group)) + geom_point() + theme(legend.position = "bottom") top_plot <- ggplot(df, aes(x = y)) + geom_density(alpha=.5, mapping = aes(fill = group))+ theme(legend.position = "none") right_plot <- ggplot(df, aes(x = x)) + geom_density(alpha=.5, mapping = aes(fill = group)) + coord_flip() + theme(legend.position = "none") 

Use the idea from Bapistes answer

 g <- ggplotGrob(scatter) g <- gtable_add_cols(g, unit(0.2,"npc")) g <- gtable_add_grob(g, ggplotGrob(right_plot)$grobs[[4]], t = 2, l=ncol(g), b=3, r=ncol(g)) g <- gtable_add_rows(g, unit(0.2,"npc"), 0) g <- gtable_add_grob(g, ggplotGrob(top_plot)$grobs[[4]], t = 1, l=4, b=1, r=4) grid.newpage() grid.draw(g) 

What produces

I used ggplotGrob(right_plot)$grobs[[4]] to manually select the panel array, but of course you could automate this

There are other alternatives: Scatterplot with marginal histograms in ggplot2

Answer 2

another variant,

 library(egg) ggarrange(top_plot, empty, scatter, right_plot, ncol=2, nrow=2, widths=c(4, 1), heights=c(1, 4)) 

Answer 3

Here is a solution in the R database. It uses the line2user function found in this question .

 par(mar = c(5, 4, 6, 6)) with(df, plot(y ~ x, bty = "n", type = "n")) with(df[df$group == 0, ], points(y ~ x, col = "dodgerblue2")) with(df[df$group == 1, ], points(y ~ x, col = "darkorange")) x0_den <- with(df[df$group == 0, ], density(x, from = par()$usr[1], to = par()$usr[2])) x1_den <- with(df[df$group == 1, ], density(x, from = par()$usr[1], to = par()$usr[2])) y0_den <- with(df[df$group == 0, ], density(y, from = par()$usr[3], to = par()$usr[4])) y1_den <- with(df[df$group == 1, ], density(y, from = par()$usr[3], to = par()$usr[4])) x_scale <- max(c(x0_den$y, x1_den$y)) y_scale <- max(c(y0_den$y, y1_den$y)) lines(x = x0_den$x, y = x0_den$y/x_scale*2 + line2user(1, 3), col = "dodgerblue2", xpd = TRUE) lines(x = x1_den$x, y = x1_den$y/x_scale*2 + line2user(1, 3), col = "darkorange", xpd = TRUE) lines(y = y0_den$x, x = y0_den$y/x_scale*2 + line2user(1, 4), col = "dodgerblue2", xpd = TRUE) lines(y = y1_den$x, x = y1_den$y/x_scale*2 + line2user(1, 4), col = "darkorange", xpd = TRUE) 

Answer 4

Here we use the option plot_grid from the plot_grid package and grid.arrange from the gridExtra package:

 library(ggplot2) library(gridExtra) library(grid) library(cowplot) df <- data.frame(y = c(rnorm(50, 1, 1), rnorm(50, -1, 1)), x = c(rnorm(50, 1, 1), rnorm(50, -1, 1)), group = factor(c(rep(0, 50), rep(1,50)))) 

Firstly, some settings: a function for retrieving the plot legend as a separate coffin, plus several reusable components:

 # Function to extract legend # https://github.com/hadley/ggplot2/wiki/Share-a-legend-between-two-ggplot2-graphs g_legend<-function(a.gplot) { tmp <- ggplot_gtable(ggplot_build(a.gplot)) leg <- which(sapply(tmp$grobs, function(x) x$name) == "guide-box") legend <- tmp$grobs[[leg]] return(legend) } # Set up reusable plot components my_thm = list(theme_bw(), theme(legend.position = "none", axis.title.y = element_blank(), axis.title.x = element_blank(), axis.text.y=element_blank(), axis.text.x=element_blank(), axis.ticks=element_blank())) marg = theme(plot.margin=unit(rep(0,4),"lines")) 

Create graphs:

 ## Empty plot empty <- ggplot() + geom_blank() + marg ## Scatterplot scatter <- ggplot(df, aes(x = x, y = y, color = group)) + geom_point() + theme_bw() + marg + guides(colour=guide_legend(ncol=2)) # Copy legend from scatterplot as a separate grob leg = g_legend(scatter) # Remove legend from scatterplot scatter = scatter + theme(legend.position = "none") ## Top density plot top_plot <- ggplot(df, aes(x = y)) + geom_density(alpha=.5, mapping = aes(fill = group)) + my_thm + marg ## Right density plot right_plot <- ggplot(df, aes(x = x)) + geom_density(alpha=.5, mapping = aes(fill = group)) + coord_flip() + my_thm + marg 

Now lay out three stories plus a legend:

 # Lay out the three plots p1 = plot_grid(top_plot, empty, scatter, right_plot, align="hv", rel_widths=c(3,1), rel_heights=c(1,3)) # Combine plot layout and legend grid.arrange(p1, leg, heights=c(10,1)) 

Answer 5

When you set the axis to element_blank() , it removes the axis and allows the chart to fill the rest of the space. Instead, set color = "white" (or any background):

 # All other code remains the same: scatter <- ggplot(df, aes(x = x, y = y, color = group)) + geom_point() + theme(legend.position = "bottom") top_plot <- ggplot(df, aes(x = y)) + geom_density(alpha=.5, mapping = aes(fill = group)) + theme(legend.position = "none")+ theme(axis.title = element_text(color = "white"), axis.text=element_text(color = "white"), axis.ticks=element_line(color = "white") ) right_plot <- ggplot(df, aes(x = x)) + geom_density(alpha=.5, mapping = aes(fill = group)) + coord_flip() + theme(legend.position = "bottom") + theme(axis.title = element_text(color = "white"), axis.text = element_text(color = "white"), axis.ticks=element_line(color = "white")) grid.arrange(top_plot, empty, scatter, right_plot, ncol=2, nrow=2, widths=c(4, 1), heights=c(1, 4)) 

I also had to add a legend to the desired plot. If you do not want this, I also suggest moving the legend in the spread inside the plot:

 scatter <- ggplot(df, aes(x = x, y = y, color = group)) + geom_point() + theme(legend.position = c(0.05,0.1)) top_plot <- ggplot(df, aes(x = y)) + geom_density(alpha=.5, mapping = aes(fill = group)) + theme(legend.position = "none")+ theme(axis.title = element_text(color = "white"), axis.text=element_text(color = "white"), axis.ticks=element_line(color = "white") ) right_plot <- ggplot(df, aes(x = x)) + geom_density(alpha=.5, mapping = aes(fill = group)) + coord_flip() + theme(legend.position = "none") + theme(axis.title = element_text(color = "white"), axis.text = element_text(color = "white"), axis.ticks=element_line(color = "white")) grid.arrange(top_plot, empty, scatter, right_plot, ncol=2, nrow=2, widths=c(4, 1), heights=c(1, 4))