Aligning a violin plot with a forest plot

Question

The violin plot (b) doesn't seem to align well with the forest plot (a). While the 5th column seems to align well, all other columns do not.

I've tried the plot_grid, ggarange, grid_draw functions and they don't seem to fix the alignment.

My result:

My code:

library(ggplot2)
library(cowplot)

#plots

a <- ggplot(data=dat_1, aes(x=varno, y=-coef, ymin=-LCI, ymax=-UCI))+ 
  geom_errorbar(width=0,size = 2,color="steelblue")+
  geom_point(size=5, color="steelblue")+
  geom_hline(yintercept=0, color="black", linetype="dashed", alpha=.5)+  #add x=0 line
  scale_y_continuous(name = "r")+
  scale_x_continuous()+
  ggtitle("A)")+
  theme_minimal()+ 
  theme(axis.text.x = element_blank(),
        axis.title.x = element_blank())

b <- ggplot(dat_2, aes(y=score, x=as.factor(group), fill=as.factor(time)))+ 
  geom_violin(position=position_dodge(0.5), trim=T)+
  scale_x_discrete()+
  labs(fill = "time",y="ratings")+
  ggtitle("B)")+
  theme_minimal()+ 
  theme(axis.text.x = element_text(angle = 90),
        axis.title.x = element_blank(),
        legend.position = "bottom")

plot_grid(a, b, align = "v", ncol = 1 )

My data:

#data
coef<-c(7.780000e-01, -2.350000e-01, -2.820000e-01, -3.090000e-01, 7.560000e-01, -0.0210000, -2.000000e-01, -0.1790000000, -2.690000e-01, -0.10300000)
LCI<-c(7.240000e-01, -3.670000e-01, -3.940000e-01, -4.310000e-01, 6.950000e-01, -0.1720000, -3.510000e-01, -0.3050000000, -4.290000e-01, -0.25600000)
UCI<-c( 8.280000e-01, -9.700000e-02, -1.450000e-01, -1.890000e-01, 8.020000e-01,  0.1240000, -6.480000e-02, -0.0369000000, -1.280000e-01,  0.05850000)
varno<-1:10
dat_1<-data.frame(cbind(coef,LCI,UCI,varno))

dat_2<- data.frame(cbind(sample(1:5, 10000, replace=T), rep(seq(1:10),1000)),c(rep(1,5000),rep(2,5000)))
colnames(dat_2)<-c("score","group","time")

Answer 1

Change 'varno' to a factor and get rid of scale_x_continuous() on plot A and you should be fine, e.g.

library(ggplot2)
library(cowplot)
  
#data
coef<-c(7.780000e-01, -2.350000e-01, -2.820000e-01, -3.090000e-01, 7.560000e-01, -0.0210000, -2.000000e-01, -0.1790000000, -2.690000e-01, -0.10300000)
LCI<-c(7.240000e-01, -3.670000e-01, -3.940000e-01, -4.310000e-01, 6.950000e-01, -0.1720000, -3.510000e-01, -0.3050000000, -4.290000e-01, -0.25600000)
UCI<-c( 8.280000e-01, -9.700000e-02, -1.450000e-01, -1.890000e-01, 8.020000e-01,  0.1240000, -6.480000e-02, -0.0369000000, -1.280000e-01,  0.05850000)
varno<-1:10
dat_1<-data.frame(cbind(coef,LCI,UCI,varno))
  
dat_2<- data.frame(cbind(sample(1:5, 10000, replace=T), rep(seq(1:10),1000)),c(rep(1,5000),rep(2,5000)))
colnames(dat_2)<-c("score","group","time")

#plots
  
a<-ggplot(data=dat_1, aes(x=factor(varno), y=-coef, ymin=-LCI, ymax=-UCI))+ 
    geom_errorbar(width=0,size = 2,color="steelblue")+
    geom_point(size=5, color="steelblue")+
    geom_hline(yintercept=0, color="black", linetype="dashed", alpha=.5)+  #add x=0 line
    scale_y_continuous(name = "r")+
    ggtitle("A)")+
    theme_minimal()+ 
    theme(axis.text.x = element_blank(),
          axis.title.x = element_blank())
  
b<-ggplot(dat_2, aes(y=score, x=factor(group), fill=factor(time)))+ 
    geom_violin(position=position_dodge(0.5), trim=T)+
    scale_x_discrete()+
    labs(fill = "time",y="ratings")+
    ggtitle("B)")+
    theme_minimal()+ 
    theme(axis.text.x = element_text(angle = 90),
          axis.title.x = element_blank(),
          legend.position = "bottom")
  
  
plot_grid(a, b, align = "v", ncol = 1 )