Styjun

This follows on from my last question. I've spent an hour or so trying to work out how to pass the variable I use to filter my dataframe to the title of the graph that is generated.

Following on from my previous questions.

library (tidyverse)
library (epitools)


# here's my made up data

DISEASE = c("Marco Polio","Marco Polio","Marco Polio","Marco Polio","Marco Polio",
 "Mumps","Mumps","Mumps","Mumps","Mumps",
 "Chicky Pox","Chicky Pox","Chicky Pox","Chicky Pox","Chicky Pox")
YEAR = c(2011, 2012, 2013, 2014, 2015,
 2011, 2012, 2013, 2014, 2015,
 2011, 2012, 2013, 2014, 2015)
VALUE = c(82,89,79,51,51,
 79,91,69,89,78,
 71,69,95,61,87)
AREA =c("A", "B","C")

DATA = data.frame(DISEASE, YEAR, VALUE,AREA)

DATA<-
DATA %>%
 mutate(POPN = case_when(
 AREA == "A" ~ 2.5,
 AREA == "B" ~ 3,
 AREA == "C" ~ 7,
 TRUE ~ 0)) %>%
 group_by(DISEASE,AREA,POPN) %>%
 count(AREA) %>%
 mutate(res = list(pois.byar(n, POPN))) %>%
 unnest()

DATA%>%filter(DISEASE== "Marco Polio")%>%
 ggplot(aes(x=AREA, y=rate)) +geom_point() +
 geom_hline(aes(yintercept=rate[AREA == "A"]), 
 linetype="dashed", color = "red")

I thought that this

 x_label = "Area!!!"
 y_label = "Rate!!!"
 DATA%>%filter(DISEASE== "Marco Polio")%>%
 ggplot(aes(x=AREA, y=rate)) +geom_point() +
 geom_hline(aes(yintercept=rate[AREA == "A"]), 
 linetype="dashed", color = "red")+
labs(x = x_label,y = y_label)+
ggtitle(DATA$DISEASE)

Why doesn't it?
It generates a chart for Marco Polio but uses Chicky Pox as the title.

What I want is (false code)
ggtitle == filter(disease)

Because what I'm going to do after this is walk and purr to get every chart for every infection and I'd like to title automatically.

Ta.

EDIT:
I've tried the suggestion below and it doesn't quite work.

I've tried this

DATA%>%filter(DISEASE== "Mumps")%>%
 ggplot(aes(x=AREA, y=rate)) +geom_point() +
 geom_hline(aes(yintercept=rate[AREA == "A"]), 
 linetype="dashed", color = "red")+
 ggtitle(paste(DISEASE))


DATA%>%filter(DISEASE== "Mumps")%>%
 ggplot(aes(x=AREA, y=rate)) +geom_point() +
 geom_hline(aes(yintercept=rate[AREA == "A"]), 
 linetype="dashed", color = "red")+
 ggtitle(as.character(DISEASE))

and no luck.

Does it have something to do with DISEASE becoming a FACTOR when it gets grouped?

It seems like you want a function where you can input a disease and have the plot created.

disease_plot <- function(disease_of_interest) 
 DATA %>%
 filter(DISEASE == disease_of_interest) %>%
 ggplot(aes(x = AREA, y = rate)) + 
 geom_point() +
 geom_hline(aes(yintercept = rate[AREA == "A"]),
 linetype = "dashed", color = "red") +
 # labs(x = x_label, y = y_label) +
 ggtitle(disease_of_interest)


disease_plot("Marco Polio")
disease_plot("Chicky Pox")
disease_plot("Mumps")

Or to have them all created at once...

map(unique(DATA$DISEASE), disease_plot)

In the end, I took the advice and help from both Stephen and Mark and cobbled it together with my original plan to walk and purr my way through it.

Here it is:

 walk(unique(DATA$DISEASE), function(disease_of_interest) 
 p <- DATA%>%filter(DISEASE== !!disease_of_interest)%>%
 ggplot(aes(x=AREA, y=rate,y=rate, 
 ymin = rate-lower, ymax = rate+upper))+ 
 geom_point() +
 geom_hline(aes(yintercept=rate[AREA == "A"]), 
 linetype="dashed", color = "red")+
 labs(x = x_label,y = y_label),+
 ggtitle(paste0("Number of ",disease_of_interest,
 " in 2018"))+
 geom_errorbar(aes(ymin=lower, ymax=upper), width=.1)
 print(p)
 ggsave(paste("drive path",disease_of_interest, "plot.png"))+
 scale_x_discrete(limits=c("C","A","B"))
 )

That is because you use the entire DATA$DISEASE as title, and it seems it just grabs the last value in that column. Much simpler is to make a filtered dataframe first, and then feed that into the plot I think.

df <- DATA%>%filter(DISEASE== "Marco Polio")

 ggplot(data = df, aes(x=AREA, y=rate)) +geom_point() +
 geom_hline(aes(yintercept=rate[AREA == "A"]), 
 linetype="dashed", color = "red")+
 labs(x = x_label,y = y_label)+
 ggtitle(df$DISEASE)

In the end I though the solution would be not to call DATA$ but merely DISEASE
However, this doesn't seem to work as expected when filtering for another Disease. I think you would have to subset DISEASE also inside the ggtitle, or better use the first function, or the other answer posted by the other user.

NOT WORKING AS EXPECTED:

DATA%>%filter(DISEASE== "Marco Polio")%>%
 ggplot(aes(x=AREA, y=rate)) +geom_point() +
 geom_hline(aes(yintercept=rate[AREA == "A"]), 
 linetype="dashed", color = "red")+
 labs(x = x_label,y = y_label)+
 ggtitle(DISEASE)