问使用grid.arrange将绘图与面对齐，并绘制没有面的绘图

EN

# load the libraries
library(ggbio)
library(Homo.sapiens)
library(GenomicRanges)
library(grid)
library(gridExtra)

# specify the chromosome area
zone <- GRanges("chr1", IRanges(1000000, 1100000))

# create the data for the patients
patcolors <- c("green", "red", "darkred")
detseg <- GRanges(seqnames = "chr1",
                  IRanges(start = rep(1000000, 3), end = rep(1100000, 3)),
                  strand = rep("*",3),
                  patient = paste("pat", 1:3, sep = "_"),
                  CN = c(-1,0.5,1))
p_pat <- autoplot(detseg, aes(color = CN, fill = CN),
                  facets = patient ~ seqnames) + 
  xlim(zone) + 
  scale_fill_gradient2(low = "blue", mid = "white", high = "red") + 
  scale_color_gradient2(low = "blue", mid = "white", high = "red") +
  theme(panel.background = element_rect(fill = "white"),
        panel.grid.major = element_blank(),
        panel.grid.minor = element_blank(),
        legend.position = "none",
        strip.background = element_rect(fill = "white"),
        strip.text.x = element_blank(),
        strip.text.y = element_text(angle = 0, hjust = 0, color = "darkgrey")) 

# create the gene model
dumGM <- autoplot(Homo.sapiens, which = zone, stat = "reduce",
                  color = "darkblue", fill = "darkblue", label = FALSE)

# align the 2 plots (but with darkgrey labels for each patient...)
p_track <- tracks(p_pat, dumGM, xlim = zone, heights = c(0.8, 0.2),
                  scale.height = unit(1.3, "lines")) + 
  theme(panel.background = element_rect(fill = "white"), 
        panel.grid.major = element_blank(),
        panel.grid.minor = element_blank())
p_track

# modify the "gtable" object to colour differently each patient
gtable_p_pat <- ggplotGrob(p_pat@ggplot)
recup_child <- lapply(gtable_p_pat$grobs,function(x) names(x[]$children))
stripy <- which(sapply(lapply(recup_child,function(x) grepl("strip.text.y",x)),
                       any ) == 1 )
for (i in 1:length(stripy)){
  colo <- patcolors[i]
  j <- stripy[i]
  gtable_p_pat$grobs[[j]]$children[[2]][]$gp$col <- colo
}
# draw the patients'plot with correctly colored labels
grid.draw(gtable_p_pat)

# get the gtable object from the gene model 
gtable_dumGM <- ggplotGrob(dumGM@ggplot)
# draw the two plots : they are not aligned...
grid.arrange(gtable_p_pat, gtable_dumGM, heights = unit(c(0.8, 0.2), "npc"))