Why does data appear to go missing when switching from geom_point to geom

I have created a large data frame (BEAVOutletWL_merge) that I am trying to produce plots pulling data from the various columns. When I input the following code:

BEAVbaro <- ggplot(BEAVOutletWL_merge, aes(x=DateTime,y=BaroPres_kpa))  
geom_point(size = .01) 
labs(x=NULL, y="BaroPres_kpa")   ylim(98, 103) 
theme() ggtitle("Beaver Marsh")
BEAVbaro

This is the plot that is produced:

However, when I try to make it a line plot using this code:

BEAVbaro <- ggplot(BEAVOutletWL_merge, aes(x=DateTime,y=BaroPres_kpa))  
geom_line(size = .5) 
labs(x=NULL, y="BaroPres_kpa")   ylim(98, 103) 
theme() ggtitle("Beaver Marsh")
BEAVbaro

This plot is produced:

The only thing that I have changed is "geom_point" to "geom_line" and the size (for aesthetic purpose) but does anyone know why the large chunk of data between 01/22 and 07/22 suddenly disappears on the line plot?

Thanks!

CodePudding user response：

Because ggplot leaves blanks in lines where there are NA values, points that are flanked by NA values won't show up with geom_line. Example:

library(ggplot2)
library(cowplot)
dd <- data.frame(x = 1:10,
                 y  = c(1, NA, 3, NA, 5, NA, 7, NA, 9, 10))

gg0 <- ggplot(dd, aes(x,y))

plot_grid(gg0   geom_point(), gg0   geom_line())

If you're OK with linear interpolation, you can fix this with na.omit():

gg0  % % na.omit(dd)   geom_line()

It would be interesting but a little more of a challenge than I have time for right now to plot a placeholder (e.g. a short horizontal dash) at the location of every NA-flanked data point ..)