R geom_smooth custom best fitted line formula-CodePudding

Geom_smooth formula

I am currently trying to fit a line to my data.

However, no fitted line is shown on the plot with none of the default methods of geom_smooth.

Here is the code that generated the plot:

p1 <- ggplot(data[ which(data$subject_id == "P121" & !is.na(data$col1)), ], aes(x = date, y= col1))   
  geom_point(colour= met.brewer("Isfahan1", 1))   
  geom_smooth(method = "stats::loess", se= FALSE)  
  theme(axis.title.x=element_blank(), axis.text.x=element_blank(),
                      axis.ticks.x=element_blank(), axis.title.y=element_blank(), axis.text.y=element_blank(),
                      axis.ticks.y =element_blank(), legend.title=element_blank())  
  scale_color_manual(values=met.brewer("Isfahan1", 13))

You can also use another method, e.g. linear

df %>%  ggplot(aes(date, col1))   
  geom_point(colour= met.brewer("Isfahan1", 1))   
  geom_smooth(formula = y~x, method = "lm", se= FALSE)   
  theme(
    axis.title.x=element_blank(), 
    axis.text.x=element_blank(),
    axis.ticks.x=element_blank(), 
    axis.title.y=element_blank(), 
    axis.text.y=element_blank(),
    axis.ticks.y=element_blank(), 
    legend.title=element_blank())  
  scale_color_manual(values=met.brewer("Isfahan1", 13))

However, pay attention to the data you give to the ggplot function. If your date variable is not of numeric type, however, plot will be created without smooth path.

df = tibble(
  date = 1:55 %>% as.character(),
  col1 = ifelse(date %in% i1, 200, 100)
)

df %>%  ggplot(aes(date, col1))   
  geom_point(colour= met.brewer("Isfahan1", 1))   
  geom_smooth(formula = y~x, method = "loess", se= FALSE)   
  theme(
    axis.title.x=element_blank(), 
    axis.text.x=element_blank(),
    axis.ticks.x=element_blank(), 
    axis.title.y=element_blank(), 
    axis.text.y=element_blank(),
    axis.ticks.y=element_blank(), 
    legend.title=element_blank())  
  scale_color_manual(values=met.brewer("Isfahan1", 13))

As you can see in this example, I changed the value of the variable date to type character (date = 1:55 %>% as.character()) which made geom_smooth to not draw anything.

CodePudding user response：

Thanks a lot for the detailed answer, everyone. The issue was about the data type I am using. It's binary (yes/no) data so it makes sense that no line will be fitted by geom_smooth. Thanks a lot again.