Pasting ggplot objects horizontally - r

Question

I'm trying to paste 16 different plots into one with a common x axis
I successfully made, plot and paste the graphs individually with grid.draw()
But i haven't been able to transform the x axis in a continuous way or at least remove the space between each graph
i attach some code to illustrate how the graphs were made.
plot1 = ggplot(map_snp %>% filter( chr == chr[1] ), aes(x=POS)) +
geom_histogram( binwidth = 2,
col=palette[2],
fill=palette[2],
alpha = .2) +
xlab("Chromosome 1") +
ylab("SNP count") +
theme_bw() +
theme(axis.text.x = element_text(angle = 0, colour = "black"),
text=element_text(family="Times New Roman", size = 12),
panel.border = element_blank(),
panel.grid.major = element_blank(),
panel.grid.minor = element_blank(),
axis.line.y = element_line(colour = "black"),
axis.line.x = element_line(colour = "black"))
par_plots <- list()
for (i in list_par) {
par_plots[[i]] = ggplot(map_snp %>% filter( chr == i ), aes(x=POS)) +
geom_histogram( binwidth = 2,
col= palette[3],
fill= palette[3],
alpha = .2) +
xlab(paste0(i)) +
theme_bw() +
theme(axis.text.x = element_text(angle = 0, colour = "black"),
text=element_text(family="Times New Roman", size = 12),
panel.border = element_blank(),
panel.grid.major = element_blank(),
panel.grid.minor = element_blank(),
axis.line.y = element_blank(),
axis.title.y = element_blank(),
axis.text.y = element_blank(),
axis.ticks.y = element_blank(),
axis.line.x = element_line(colour = "black"))
}
impar_plots <- list()
for (i in list_impar) {
impar_plots[[i]] = ggplot(map_snp %>% filter( chr == i ), aes(x=POS)) +
geom_histogram( binwidth = 2,
col= palette[2],
fill=palette[2],
alpha = .2) +
xlab(paste0(i)) +
theme_bw() +
theme(axis.text.x = element_text(angle = 0, colour = "black"),
text=element_text(family="Times New Roman", size = 12),
panel.border = element_blank(),
panel.grid.major = element_blank(),
panel.grid.minor = element_blank(),
axis.line.y = element_blank(),
axis.title.y = element_blank(),
axis.text.y = element_blank(),
axis.ticks.y = element_blank(),
axis.line.x = element_line(colour = "black"))
}
grid.newpage()
png(paste("./snp_map.png"), width = 15*4.5, height = 8, res = 320, units = "cm", pointsize = 12, bg = "white")
grid.draw(cbind(ggplotGrob(plot1),
ggplotGrob(par_plots$`Chromosome 2`),
ggplotGrob(impar_plots$`Chromosome 3`),
ggplotGrob(par_plots$`Chromosome 4`),
ggplotGrob(impar_plots$`Chromosome 5`),
ggplotGrob(par_plots$`Chromosome 6`),
ggplotGrob(impar_plots$`Chromosome 7`),
ggplotGrob(par_plots$`Chromosome 8`),
ggplotGrob(impar_plots$`Chromosome 9`),
ggplotGrob(par_plots$`Chromosome 10`),
ggplotGrob(impar_plots$`Chromosome 11`),
ggplotGrob(par_plots$`Chromosome 12`),
ggplotGrob(impar_plots$`Chromosome 13`),
ggplotGrob(par_plots$`Chromosome 14`),
ggplotGrob(impar_plots$`Chromosome 15`),
ggplotGrob(par_plots$`Chromosome 16`),
size = "last"))
dev.off()
SNP MAP

Answer 1

I can get rid of most of the border, but not quiiiiite all. Here using an example from built in diamonds data set from ggplot2.
par_plots <- list()
cuts = unique(diamonds$cut)
for (c in as.numeric(cuts)) {
par_plots[[c]] = ggplot(diamonds %>% filter(as.numeric(cut) == c),
aes(x = price)) +
geom_histogram() +
scale_x_continuous(expand = expansion(0)) +
xlab(paste0(i)) +
theme_classic() +
theme(axis.text.x = element_text(angle = 0, colour = "black"),
text=element_text(family="Times New Roman", size = 12),
plot.margin = unit(c(0,0,0,0), "cm"),
panel.border = element_blank(),
panel.grid.major = element_blank(),
panel.grid.minor = element_blank(),
axis.line.y = element_blank(),
axis.title.y = element_blank(),
axis.text.y = element_blank(),
axis.ticks.y = element_blank(),
axis.line.x = element_line(colour = "black"))
}
library(grid)
grid.newpage()
# png(paste("./snp_map.png"), width = 15*4.5, height = 8, res = 320, units = "cm", pointsize = 12, bg = "white")
grid.draw(cbind(ggplotGrob(par_plots[[1]]),
ggplotGrob(par_plots[[2]]),
ggplotGrob(par_plots[[3]]),
ggplotGrob(par_plots[[4]])))
dev.off()