Consistent width for geom_bar in the event of missing data

Question

Is there a way to set a constant width for geom_bar() in the event of missing data in the time series example below? I've tried setting width in aes() with no luck. Compare May '11 to June '11 width of bars in the plot below the code example.

colours <- c("#FF0000", "#33CC33", "#CCCCCC", "#FFA500", "#000000" ) iris$Month <- rep(seq(from=as.Date("2011-01-01"), to=as.Date("2011-10-01"), by="month"), 15)  colours <- c("#FF0000", "#33CC33", "#CCCCCC", "#FFA500", "#000000" ) iris$Month <- rep(seq(from=as.Date("2011-01-01"), to=as.Date("2011-10-01"), by="month"), 15) d<-aggregate(iris$Sepal.Length, by=list(iris$Month, iris$Species), sum) d$quota<-seq(from=2000, to=60000, by=2000) colnames(d) <- c("Month", "Species", "Sepal.Width", "Quota") d$Sepal.Width<-d$Sepal.Width * 1000 g1 <- ggplot(data=d, aes(x=Month, y=Quota, color="Quota")) + geom_line(size=1) g1 + geom_bar(data=d[c(-1:-5),], aes(x=Month, y=Sepal.Width, width=10, group=Species, fill=Species), stat="identity", position="dodge") + scale_fill_manual(values=colours) 

Answer 1

Some new options for position_dodge() and the new position_dodge2(), introduced in ggplot2 3.0.0 can help.

You can use preserve = "single" in position_dodge() to base the widths off a single element, so the widths of all bars will be the same.

ggplot(data = d, aes(x = Month, y = Quota, color = "Quota")) +       geom_line(size = 1) +       geom_col(data = d[c(-1:-5),], aes(y = Sepal.Width, fill = Species),                position = position_dodge(preserve = "single") ) +       scale_fill_manual(values = colours) 

Using position_dodge2() changes the way things are centered, centering each set of bars at each x axis location. It has some padding built in, so use padding = 0 to remove.

ggplot(data = d, aes(x = Month, y = Quota, color = "Quota")) +       geom_line(size = 1) +       geom_col(data = d[c(-1:-5),], aes(y = Sepal.Width, fill = Species),                position = position_dodge2(preserve = "single", padding = 0) ) +       scale_fill_manual(values = colours)