Generate two plots with same x axis breaks - r

Question

I have two plots I want the x axes being broken by the same way.
This is the code for plot 1:
m <- read.csv('Finalfor1lowergreaterthan1.csv', header=T, row.names=1)
m <- m[m$SVM.Count >= 40,]
boxOdds = m$Odd
df <- data.frame(
yAxis = length(boxOdds):1,
boxnucleotide = m$Position,
boxCILow = m$lower,
boxCIHigh = m$upper,
Mutation = m$Resistance)
ticksy <- c(seq(0,0.3,by=.1), seq(0, 1, by =.5), seq(0, 20, by =5), seq(0, 150, by =50))
ticksx <- c(seq(0,300,by=25))
p <- ggplot(df,
aes(x = boxnucleotide, y = boxOdds, colour=Mutation, label=rownames(m)))
p1 <- p +
geom_errorbar(aes(ymax = boxCIHigh, ymin = boxCILow), size = .5, height = .01) +
geom_point(size = 1) +
theme_bw() +
theme(panel.grid.minor = element_blank()) +
scale_y_continuous(breaks=ticksy, labels = ticksy) +
scale_x_continuous(breaks=ticksx, labels = ticksx) +
coord_trans(y = "log10") +
ylab("Odds ratio (log scale)") +
scale_color_manual(values=c("#00BFC4","#F8766D","#619CFF")) +
xlab("Integrase nucleotide position") +
geom_text(size=2,hjust=0, vjust=0)
Then I have another plot:
m <- read.csv('Finalfor20lowergreaterthan1.csv', header=T, row.names=1)
#m <- m[m$SVM.Count >= 40, ]
boxOdds = m$Odd
df <- data.frame(
yAxis = length(boxOdds):1,
boxnucleotide = m$Position,
boxCILow = m$lower,
boxCIHigh = m$upper,
Mutation = m$Resistance)
ticksy <- c(seq(0,0.3,by=.1), seq(0, 1, by =.5), seq(0, 20, by =5), seq(0, 150, by =50))
ticksx <- c(seq(0,300,by=25))
p <- ggplot(df,
aes(x = boxnucleotide, y = boxOdds, colour=Mutation, label=rownames(m)))
p1 <- p +
geom_errorbar(aes(ymax = boxCIHigh, ymin = boxCILow), size = .5, height = .01) +
geom_point(size = 1) +
theme_bw() +
theme(panel.grid.minor = element_blank()) +
scale_y_continuous(breaks=ticksy, labels = ticksy) +
scale_x_continuous(breaks=ticksx, labels = ticksx) +
coord_trans(y = "log10") +
ylab("Odds ratio (log scale)") +
scale_color_manual(values=c("#00BFC4","#F8766D","#619CFF")) +
xlab("Integrase nucleotide position") +
geom_text(size=2,hjust=0, vjust=0)
Why is plot 1 starting from 75 on x axis and plot 2 starting at 100...how can plot2 start at 75 as well and being scaled like plot 1.
The two codes get the same piece of: ticksx <- c(seq(0, 300, by=25))

Answer 1

A good technique to align the axis range on different plots is to use expand_limits.
You can simply use p1 + expand_limits(x=c(0, 300)). This will ensure the x-axis contains at least 0 and 300 on all your plots. You can also control the y-axis range by using the y argument.
From ?expand_limits:
Sometimes you may want to ensure limits include a single value, for all panels or all plots. This function is a thin wrapper around geom_blank() that makes it easy to add such values.