Question

I like to run method=”loess” on my data set and if errors, I like to try the lm method. Below is my code to do this, but it is still failing, any ideas?

df

Date  Duration  Athlete
1/1/2012  60    A
1/2/2012  30    A
1/3/2012  10    B
1/1/2012  5     C
1/2/2012  5     C
1/4/2012  4     C

ggplot(df, aes(Date, Duration, group=Athlete)) + geom_point(position="jitter", size=0.5) +theme_solarized(light = FALSE) +  geom_smooth(method=ifelse(class(try(loess(Duration~Date, df)))=="try-error", "lm","loess"), se=T)

I get this error:

Error in simpleLoess(y, x, w, span, degree, parametric, drop.square, normalize,  :
  NA/NaN/Inf in foreign function call (arg 2)
In addition: Warning message:
In simpleLoess(y, x, w, span, degree, parametric, drop.square, normalize,  :
  NAs introduced by coercion
Error in function (el, elname)  :

Answer 1

I think it is better to know which smoothing method you pass to the ggplot2 stat engine.

For example:

mym <- "loess"
tryCatch(loess(Duration~Date, dat), 
         error = function(e) mym <<- "lm")

Then

ggplot(dat, aes(Date, Duration, group=Athlete)) + 
  geom_point(position="jitter", size=0.5) + 
  geom_smooth(method=mym, se=T)