Question

I really like how my dotplot looks with facet_wrap (facet labels on top) but I’d ideally like to be able to pass it a space = “free_x” so the facets are sized appropriately. The problem with facet_grid is that the facet labels move to the side of the plot, which in this case doesn’t work well because I want each panel to be separated.

Code follows:

# load data
plotdat <- structure(list(level = c("Lost (N =328)", "Won (N =75)", "Lost (N =10)", 
                        "Won (N =65)", "Challenger (N =318)", "Incumbent (N =85)", "Arab (N =7)", 
                        "Black (N =222)", "East Asian (N =40)", "Latino (N =107)", "Other (N =10)", 
                        "South Asian (N =17)", "Not (N =252)", "Statewide (N =151)"), 
                mean = c(0.59834264517378, 0.645308353066667, 0.6382179387, 
                        0.646399186046154, 0.595756747751572, 0.649457274258823, 
                        0.682776774142857, 0.557334915725225, 0.6654738063, 0.68260777364486, 
                        0.6061308922, 0.613378378411765, 0.616298597519841, 0.591703758423841
                ), se = c(0.00597842210656315, 0.0113080614816089, 0.044927778673023, 
                        0.011274258338002, 0.00622316181664198, 0.00900474213888581, 
                        0.0247451786416615, 0.00690804451732034, 0.0116899960061005, 
                        0.00777478853477299, 0.0183766282892234, 0.0166464474073244, 
                        0.00669527297092827, 0.00887170639612841), N = c(328L, 75L, 
                        10L, 65L, 318L, 85L, 7L, 222L, 40L, 107L, 10L, 17L, 252L, 
                        151L), var = structure(c(1L, 1L, 2L, 2L, 3L, 3L, 4L, 4L, 
                                4L, 4L, 4L, 4L, 5L, 5L), .Label = c("Primary Election", "General Election", 
                                "Incumbency", "Race", "Statewide District"), class = "factor")), .Names = c("level", 
                "mean", "se", "N", "var"), row.names = c(NA, 14L), class = "data.frame")
library('ggplot2')

# with facet_wrap:
ggplot(plotdat, aes(x = mean, xmin = mean-se, xmax = mean+se, y = level)) + 
    geom_point() + geom_segment( aes(x = mean-se, xend = mean+se, 
                    y = level, yend=level)) +
    facet_wrap(~var, ncol=1, scales = "free_y") +
    theme_bw() + opts(axis.title.x = theme_text(size = 12, vjust = .25))+ 
    xlab("Mean V (Brightness) for Candidate's Face") + ylab("") +
    opts(title = expression("Skin Complexion for 2010 Minority Candidates"))

# with facet_grid:
ggplot(plotdat, aes(x = mean, xmin = mean-se, xmax = mean+se, y = level)) + 
    geom_point() + geom_segment( aes(x = mean-se, xend = mean+se, 
                    y = level, yend=level)) +
    facet_grid(var~., scales = "free_y", space = "free_y") +
    theme_bw() + opts(axis.title.x = theme_text(size = 12, vjust = .25))+ 
    xlab("Mean V (Brightness) for Candidate's Face") + ylab("") +
    opts(title = expression("Skin Complexion for 2010 Minority Candidates"))

Any suggestions? Thanks very much!

Answer 1

Update Using the ggplot grob, this is fairly easy to do. See here or here

ggplot grob version

library(ggplot2)
library(dplyr)
library(grid)

# Get the plot; plotdat data frame is below
p = ggplot(plotdat, aes(x = mean, xmin = mean-se, xmax = mean+se, y = level)) + 
    geom_point() + geom_segment( aes(x = mean-se, xend = mean+se, 
                    y = level, yend=level)) +
    facet_wrap(~var, ncol=1, scales = "free_y") +
    theme_bw() + theme(axis.title.x = element_text(size = 12, vjust = .25))+ 
    xlab("Mean V (Brightness) for Candidate's Face") + ylab("") +
    ggtitle("Skin Complexion for 2010 Minority Candidates")


# From 'plotdat', get the number of 'levels' for each 'var'.
# That is, the number y-breaks in each panel.
N <- plotdat %>% group_by(var) %>% 
   summarise(count = n()) %>% 
   `[[`(2)

# Get the ggplot grob
gt = ggplotGrob(p) 

# Get the locations of the panels in the gtable layout.
panels <- gt$layout$t[grepl("panel", gt$layout$name)]

# Replace the default panel heights with relative heights
gt$heights[panels] <- unit(N, "null")

## Draw gt
grid.newpage()
grid.draw(gt)

Original answer
EDIT: Updated to ggplot2 version 0.9.3.1

This is not going to answer your question. It tweaks the facet_grid look.

I’m not sure what you mean by “each panel being separated”. If you are concerned that the strip text in the facet_grid plot extends beyond the boundaries of the strip, the text can be rotated using theme(strip.text.y = element_text(angle = 0)). Furthermore, the text can be made to wrap round to multiple lines using str_wrap from the stingr package.

# load data
plotdat <- structure(list(level = c("Lost (N =328)", "Won (N =75)", "Lost (N =10)", 
                        "Won (N =65)", "Challenger (N =318)", "Incumbent (N =85)", "Arab (N =7)", 
                        "Black (N =222)", "East Asian (N =40)", "Latino (N =107)", "Other (N =10)", 
                        "South Asian (N =17)", "Not (N =252)", "Statewide (N =151)"), 
                mean = c(0.59834264517378, 0.645308353066667, 0.6382179387, 
                        0.646399186046154, 0.595756747751572, 0.649457274258823, 
                        0.682776774142857, 0.557334915725225, 0.6654738063, 0.68260777364486, 
                        0.6061308922, 0.613378378411765, 0.616298597519841, 0.591703758423841
                ), se = c(0.00597842210656315, 0.0113080614816089, 0.044927778673023, 
                        0.011274258338002, 0.00622316181664198, 0.00900474213888581, 
                        0.0247451786416615, 0.00690804451732034, 0.0116899960061005, 
                        0.00777478853477299, 0.0183766282892234, 0.0166464474073244, 
                        0.00669527297092827, 0.00887170639612841), N = c(328L, 75L, 
                        10L, 65L, 318L, 85L, 7L, 222L, 40L, 107L, 10L, 17L, 252L, 
                        151L), var = structure(c(1L, 1L, 2L, 2L, 3L, 3L, 4L, 4L, 
                                4L, 4L, 4L, 4L, 5L, 5L), .Label = c("Primary Election", "General Election", 
                                "Incumbency", "Race", "Statewide District"), class = "factor")), .Names = c("level", 
                "mean", "se", "N", "var"), row.names = c(NA, 14L), class = "data.frame")
library('ggplot2')
library(stringr)

plotdat$var = str_wrap(plotdat$var, width = 10)

# with facet_grid:
ggplot(plotdat, aes(x = mean, xmin = mean-se, xmax = mean+se, y = level)) + 
    geom_point() + geom_segment( aes(x = mean-se, xend = mean+se, 
                    y = level, yend=level)) +
    facet_grid(var~., scales = "free_y", space = "free_y") +
    theme_bw() + 
    ggtitle("Skin Complexion for 2010 Minority Candidates") +
    xlab("Mean V (Brightness) for Candidate's Face") + ylab("") +
    theme(axis.title.x = element_text(size = 12, vjust = .25), 
          strip.text.y = element_text(angle = 0))

If “panels to be separated” means “additional space between the panels”, use theme(panel.margin = unit(2, "line"), after loading grid.

library(grid)
ggplot(plotdat, aes(x = mean, xmin = mean-se, xmax = mean+se, y = level)) + 
    geom_point() + geom_segment( aes(x = mean-se, xend = mean+se, 
                    y = level, yend=level)) +
    facet_grid(var~., scales = "free_y", space = "free_y") +
    theme_bw() + 
    ggtitle("Skin Complexion for 2010 Minority Candidates") +
    xlab("Mean V (Brightness) for Candidate's Face") + ylab("") +
    theme(axis.title.x = element_text(size = 12, vjust = .25), 
          strip.text.y = element_text(angle = 0),
          panel.margin = unit(2, "lines"))