R help - Jul 2015 - ggplot2 - geom_text() with date as x-axis

I am trying to annotate a graph using geom_text() and I seem to be
misunderstanding how to use a date in the co-ordinates---or, at least, I think
that is the problem. Code is below.

Can anyone give me a suggestion of where I am going wrong?

Thanks,
John

John Kane
Kingston ON Canada
###==========================================ibrary(ggplot2)
library(lubridate)
ins  <-  structure(list(td = structure(c(1437804720, 1437824100, 1437836220, 
1437851580, 1437863460, 1437878640, 1437890640, 1437904800, 1437918240, 
1437926100, 1437941340, 1437951240), tzone = "UTC", class =
c("POSIXct",
"POSIXt")), glucose = c(328L, 390L, 358L, 387L, 440L, 328L, 365L, 
450L, 467L, 477L, 408L, 457L), dose = c(NA, 0.5, NA, NA, 0.5, 
NA, NA, 0.5, NA, NA, NA, 0.5)), .Names = c("td", "glucose",
"dose"
), row.names = c(NA, -12L), class = "data.frame")

anon  <- na.omit(ins)  # extract shots 

texdat =  ymd_hm("2015-07-26 20:09")

glucose  <-  ggplot(ins, aes(td, glucose)) + geom_point(colour =
"red") + geom_line(colour = "blue")
p1  <-  glucose + annotate("text", x = texdat, y = 500, label =
anon[ ,3 ], cex = 3)
p1

# Now the problem
 p2  <-  p1 +  geom_text(x = texdat, y = 400 , size = 2,  label=
"Glucose")
p2
###============================================
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I'm a bit confused what you're trying to accomplish - the mix of
annotate() and geom_text() is confusing. The following code works for
me, and I think might be what you want:

ggplot(ins, aes(td, glucose)) +
  geom_point(colour = "red") +
  geom_line(colour = "blue") +
  annotate("text", x = texdat, y = 500, label = "Glucose",
cex = 3)

Hadley

On Thu, Jul 30, 2015 at 10:23 AM, John Kane <jrkrideau at inbox.com>
wrote:
> I am trying to annotate a graph using geom_text() and I seem to be
misunderstanding how to use a date in the co-ordinates---or, at least, I think
that is the problem. Code is below.
>
> Can anyone give me a suggestion of where I am going wrong?
>
> Thanks,
> John
>
> John Kane
> Kingston ON Canada
> ###==========================================> ibrary(ggplot2)
> library(lubridate)
> ins  <-  structure(list(td = structure(c(1437804720, 1437824100,
1437836220,
> 1437851580, 1437863460, 1437878640, 1437890640, 1437904800, 1437918240,
> 1437926100, 1437941340, 1437951240), tzone = "UTC", class =
c("POSIXct",
> "POSIXt")), glucose = c(328L, 390L, 358L, 387L, 440L, 328L, 365L,
> 450L, 467L, 477L, 408L, 457L), dose = c(NA, 0.5, NA, NA, 0.5,
> NA, NA, 0.5, NA, NA, NA, 0.5)), .Names = c("td",
"glucose", "dose"
> ), row.names = c(NA, -12L), class = "data.frame")
>
> anon  <- na.omit(ins)  # extract shots
>
> texdat =  ymd_hm("2015-07-26 20:09")
>
> glucose  <-  ggplot(ins, aes(td, glucose)) + geom_point(colour =
"red") + geom_line(colour = "blue")
> p1  <-  glucose + annotate("text", x = texdat, y = 500, label
= anon[ ,3 ], cex = 3)
> p1
>
> # Now the problem
>  p2  <-  p1 +  geom_text(x = texdat, y = 400 , size = 2,  label=
"Glucose")
> p2
> ###============================================>
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