Align geom_point data with geom_col data when combining with patchwork-CodePudding

I am working to create two graphics and merging them into a single graphic using patchwork. The x-axis are dates and the top graph is a geom_line/geom_point graph and the bottom graph is created using geom_col. When combined, I'd like to have the points in the top graphic align with the center of columns in the bottom graphic.

I was hoping that b/c the x-axis spans the same dates, the points would align with the center of columns. In several attempts, I was unable to center the dots above the column. The resulting graphic (and the code) is below.

library(patchwork)


nn<-15
p1data = tibble(date=ymd('2021-01-01')   days(0:(nn-1)), values=floor(runif(nn, 5.0, 75)))

p2data <- tibble(initdate = ymd('2021-01-01') days(0:(nn-1)), data=runif(nn,4,10))

# set up a tibble to shade in every other day
shade <- tibble(min=ymd('2021-01-01 00:00') days(0:20),max=lead(min))
# Remove every other row
toDelete <- seq(1,dim(shade)[1],by=2)
shade <- shade[-toDelete,]

plot_limits = c(ymd('2021-01-01'),ymd('2021-01-16'))

# Orginal Attempt 
p1 <- p1data %>% 
  ggplot()   
  geom_rect(data=shade, aes(xmin=min,xmax=max,ymin=-Inf,ymax=Inf),fill='grey80' )   
  geom_line(aes(x=date,y=values))   
  geom_point(aes(x=date,y=values),color='red',size=3)  
  scale_x_date(expand=c(0,0),
                   date_breaks = '1 days',
                   date_labels = '%b-%d',
                   limits=plot_limits)  
  labs(title='two plots combined')   
  theme_bw()   
  theme(plot.title=element_text(hjust=0.5), 
        axis.text.x=element_blank(),
        axis.ticks.x=element_blank(),
        axis.title.x=element_blank())
  

p2 <- p2data %>%  
  ggplot()   
  geom_col(aes(x=initdate,y=data, fill=data))   
  scale_x_date(expand=c(0,0),date_breaks = '1 days',date_labels = '%b-%d')  
  theme_bw()   
  theme(plot.title=element_blank(),
        axis.title.x=element_blank(),
        axis.text.x=element_text(angle=0),
        legend.direction = "horizontal", 
        legend.position = "bottom",
        legend.key.width=unit(1.25,"cm"),
        legend.key.height=unit(.25,"cm"),
        legend.box = "vertical",
        legend.box.background = element_blank(),
        legend.title = element_text(face = "bold"),
        legend.spacing = unit(1,"cm"),
        legend.justification = "center",
        legend.margin = margin(0.,0.,0.,0., unit="cm"),
        legend.background = element_blank(),
        plot.margin = margin(0, 0, 0, 0, "cm")
  )

p1/p2

Are there other ways to achieve center the dots for each day in the top graph with the column in the bottom graph?

CodePudding user response：

While working to prepare this question, I was able to develop a solution. The solution is to use datetime formats for the top graphic instead of just date. The datetimes associated with the data can then be set to YYYY-MM-DD 12:00. The data is then plotted in the middle of the day rather than at the start of each day.

The resulting graphic is:

And the code that achieves it is:

# The solution that works
# Specify the dates in datetime format and use the hours to center the data in the day. 

# The shade data for daily shades must be in datetime asd well.
# set up a tibble to shade in every other day
shade_dtm <- tibble(min=ymd_hm('2021-01-01 00:00') days(0:20),max=as_datetime(lead(min)))
# Remove every other row
toDelete <- seq(1,dim(shade_dtm)[1],by=2)
shade_dtm <- shade_dtm[-toDelete,]

# create data
p1data_dtm = tibble(date=ymd_hm('2021-01-01 12:00')   days(0:(nn-1)), values=floor(runif(nn, 5.0, 75)))

plot_limits_dtm = c(ymd_hm('2021-01-01 00:00'),ymd_hm('2021-01-16 00:00'))

p1 <- p1data_dtm %>% 
      ggplot()   
      geom_rect(data=shade_dtm, aes(xmin=min,xmax=max,ymin=-Inf,ymax=Inf),fill='grey80' )   
      geom_line(aes(x=date,y=values))   
      geom_point(aes(x=date,y=values),color='red',size=3)  
      scale_x_datetime(expand=c(0,0),
                       date_breaks = '1 days',
                       date_labels = '%b-%d',
                       limits=plot_limits_dtm)  
      labs(title='two plots combined: data aligned')   
      theme_bw()   
      theme(plot.title=element_text(hjust=0.5), 
        axis.text.x=element_blank(),
        axis.ticks.x=element_blank(),
        axis.title.x=element_blank())


p2 <- p2data %>%  
      ggplot()   
      geom_col(aes(x=initdate,y=data, fill=data))   
      scale_x_date(expand=c(0,0),date_breaks = '1 days',date_labels = '%b-%d')  
      theme_bw()   
      theme(plot.title=element_blank(),
        axis.title.x=element_blank(),
        axis.text.x=element_text(angle=0),
        legend.direction = "horizontal", 
        legend.position = "bottom",
        legend.key.width=unit(1.25,"cm"),
        legend.key.height=unit(.25,"cm"),
        legend.box = "vertical",
        legend.box.background = element_blank(),
        legend.title = element_text(face = "bold"),
        legend.spacing = unit(1,"cm"),
        legend.justification = "center",
        legend.margin = margin(0.,0.,0.,0., unit="cm"),
        legend.background = element_blank(),
        plot.margin = margin(0, 0, 0, 0, "cm")
  )

p1/p2