[R] Axis whitout all the row, that contains time

[Rui Barradas]

Hello,

In order to select every 20 s, set the date_breaks = "20 secs", not the 
breaks.
The axis labels are also formatted, with date_labels, standard datetime 
format strings are used for this. And rotated, not part of the question.

# Create some data
set.seed(2021)
time <- seq(as.POSIXct("2021-02-11"), as.POSIXct("2021-02-11 00:29:59"), 
by = "1 secs")
y <- cumsum(rnorm(length(time)))
df1 <- data.frame(time, y)

# Plot the data
library(ggplot2)

ggplot(df1, aes(time, y)) +
   geom_line() +
   scale_x_datetime(date_breaks = "20 secs", date_labels = "%M:%S") +
   theme(axis.text.x = element_text(angle = 90, vjust = 0.5, hjust=1, 
size = 5))


Hope this helps,

Rui Barradas

Às 15:05 de 12/02/21, Informatique escreveu:
> Hello,
> 
> i'm using Rstudio from a few day, and i have some information in a CVS file, take every five second, format of the time is HH:MM:SS.
> I use the hour on the X axis, but i don't want having all the time print. For example only every 10 values.
> 
> I think it will be possible with   scale_x_datetime(breaks = date_breaks(XXX)
> 
> but i don't understand how select every 20 s.
> 
> Thank's for your help
> 
> François-marie BILLARD
>