How to get r to not remove a row in ggplot

I'm trying to produce a graph of growth rates over time based upon the following data which has blanks in two groups.

When I try to make a growth plot of this using geom_line to join points there is no line for group c.

I'm just wondering if there is anyway to fix this

CodePudding user response：

One option would be to get rid of the missing values which prevent the points to be connected by the line:

Making use of the code from the answer I provided on your previous question but adding tidyr::drop_na:

Growthplot <- data.frame(
  Site = letters[1:4],
  July = 0,
  August = c(1, -1, NA, 2),
  September = c(3, 2, 3, NA)
)

library(ggplot2)
library(tidyr)
library(dplyr, warn=FALSE)

growth_df <- Growthplot %>%
  pivot_longer(-Site, names_to = "Month", values_to = "Length") %>%
  mutate(Month = factor(Month, levels = c("July", "August", "September"))) %>%
  drop_na()

ggplot(growth_df, aes(x = Month, y = Length, colour = Site, group = Site))  
  geom_point()  
  geom_line() 
  labs(color = "Site", x = "Month", y = "Growth in cm")     
  theme(axis.line = element_line(colour = "black", size = 0.24))