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I'm trying to improve a simple but important detail in my facet_grid graphic.

I played with scale and space parameteres of facet_grid() function. But I would like to increase the height only for the bottom facet in order to be possible to read the sample count that appears cut off in the graph (highlighted in red). See Image1. The code used is:

    ggplot(salm_data, aes(x=SALM) ) + geom_bar(stat = "count", position = position_dodge())
 + facet_grid(YEAR ~ TYPE, scales = "free_x", space = "free") 
 +  geom_text(size=2.5, stat = "count", aes(label = after_stat(count)), vjust = -0.3) +theme_bw() + labs(y="Number of samples") + 
theme(panel.grid.minor = element_blank())+
 labs(x=expression(paste(italic("Klebsiella spp."), " ")))

Image 1: Image1

To try to overcome this "problem" I tried including next code to enlarge the Y-axis:

scale_y_continuous(breaks = seq(from = 0, to = 300, by = 40))

But I'm not capable to improve the situation (see Image2).

Image 2: Image2

Could you help me with some ideas to overcome this scenario?

Thanks on advance for your help/comments,

Magi

MagíBC
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    The [`ggh4x::force_panelsizes()`](https://teunbrand.github.io/ggh4x/articles/Facets.html#panel-sizes-1) might help you finetune facet proportions. (Disclaimer: I wrote that) – teunbrand Mar 18 '22 at 14:07

2 Answers2

2

Grid graphics enable you to modify the widths and heights of ggplot() objects.

Sample code:

library(grid)   



gg = ggplot(salm_data, aes(x=type) ) + 
      geom_bar(stat = "count", position = position_dodge())+ 
      facet_grid(year ~ type, scales = "free_x", space = "free")+
      geom_text(size=2.5, stat = "count", aes(label = after_stat(count)), vjust = -0.3) +
      theme_bw() + 
      labs(y="Number of samples") + 
      theme(panel.grid.minor = element_blank())+
      labs(x=expression(paste(italic("Klebsiella spp."), " ")))
    
    
    
gt = ggplot_gtable(ggplot_build(g))
gt$widths[7] = 4*gt$widths[7]  # modify panel-1-2 and panel-2-2  
gt$heights[7] = 4*gt$heights[7] #modify panel-1-2 and panel-2-2 
grid.draw(gt)

Sample plot:

enter image description here Sample data:

salm_data<-structure(list(type = c("A", "B", "C", "D", "A", "B", "C", "D", 
"A", "B", "C", "D", "A", "C", "A", "B", "C", "D", "A", "B", "C", 
"D", "A", "B", "C", "D", "A", "C", "A", "B", "C", "D", "A", "B", 
"C", "D", "A", "B", "C", "D", "A", "C", "A", "B", "C", "D", "A", 
"B", "C", "D", "A", "B", "C", "D", "A", "C", "A", "B", "C", "D", 
"A", "B", "C", "D", "A", "B", "C", "D", "A", "C", "A", "B", "C", 
"D", "A", "B", "C", "D", "A", "B", "C", "D", "A", "C", "A", "A", 
"A", "A", "A", "A", "A", "A", "A", "A", "A", "A", "A", "A", "A", 
"A", "A", "A", "A", "A", "A", "A", "A", "A", "A", "A", "A", "A"
), year = c(2001, 2001, 2001, 2001, 2001, 2002, 2001, 2002, 2001, 
2002, 2001, 2002, 2002, 2002, 2001, 2001, 2001, 2001, 2001, 2002, 
2001, 2002, 2001, 2002, 2001, 2002, 2002, 2002, 2001, 2001, 2001, 
2001, 2001, 2002, 2001, 2002, 2001, 2002, 2001, 2002, 2002, 2002, 
2001, 2001, 2001, 2001, 2001, 2002, 2001, 2002, 2001, 2002, 2001, 
2002, 2002, 2002, 2001, 2001, 2001, 2001, 2001, 2002, 2001, 2002, 
2001, 2002, 2001, 2002, 2002, 2002, 2001, 2001, 2001, 2001, 2001, 
2002, 2001, 2002, 2001, 2002, 2001, 2002, 2002, 2002, 2001, 2001, 
2001, 2001, 2001, 2001, 2001, 2001, 2001, 2001, 2001, 2001, 2001, 
2001, 2001, 2001, 2001, 2001, 2001, 2001, 2001, 2001, 2001, 2001, 
2001, 2001, 2001, 2001)), class = "data.frame", row.names = c(NA, 
-112L))
Rfanatic
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1

Many thanks @Rfanatic. That's just the thing that I desired.

I create the gtable from package grid as you indicated but I have used also the library gtable to help me to discover the panel codification for my case. Here's the code if can also help someone in the future:

gt <- ggplot_gtable(ggplot_build(gg))
gt$widths[14] = 1*gt$widths[14]    
gt$heights[14] = 4*gt$heights[14]  
grid.draw(gt)

I use the position 14 because it was the row position number for the square that I have problems:

library(gtable)
gtable_show_layout(gt)

But the best for me it has been print the TableGrob:

print(gt)
#17 1 (14-14,11-11) panel-4-4 gTree[panel-16.gTree.8635]

I was interested in panel-4-4 in my example (only I printed here this line of the gt output). Moreover, due to I want to change the row height and width, I pick up 14 instead of 11.

Thanks .

MagíBC
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