Date format

$date is a factor, which is coded as numeric values internally, which
as.date sees as numeric, and therefore:
"as.Date will accept numeric data (the number of days since an epoch),
but only if origin is supplied." (from ?as.Date)

You need to supply a format argument to as.Date to get it to handle
the factor properly; e.g.
"%d.%m.%Y"  should work. See ?strptime for formatting details.

Bert Gunter

"The trouble with having an open mind is that people keep coming along
and sticking things into it."
-- Opus (aka Berkeley Breathed in his "Bloom County" comic strip )

On Sat, May 9, 2020 at 5:31 PM Medic <mailiPadpost at gmail.com> wrote:

I took a SAMPLE CODE (for Connected scatterplot) from the R gallery
and applied to MY DATA, but got:
"Error in as.Date.numeric(mydata$date) : 'origin' must be supplied".
P.S. I can not understand ?as.Date()

SAMPLE CODE
library(ggplot2)
library(dplyr)
library(hrbrthemes)
data <-

read.table("https://raw.githubusercontent.com/holtzy/data_to_viz/master/Example_dataset/3_TwoNumOrdered.csv",

header=T)

str(data)
'data.frame': 1822 obs. of  2 variables:
 $ date : chr  "2013-04-28" "2013-04-29" "2013-04-30" "2013-05-01"

...

 $ value: num  136 147 147 140 126 ...

data$date <- as.Date(data$date)

# Plot
data %>%
  tail(10) %>%
  ggplot( aes(x=date, y=value)) +
    geom_line( color="grey") +
    geom_point(shape=21, color="black", fill="#69b3a2", size=6) +
    theme_ipsum() +
    ggtitle("Evolution of bitcoin price")


MY DATA
mydata <- read.table("E:/mydata.csv", header=TRUE, sep=";", dec=",")

str(mydata)
'data.frame': 7 obs. of  2 variables:
 $ date : chr  "01.01.2000" "02.01.2000" "03.01.2000" "04.01.2000"

...

 $ value: int  11 12 13 14 15 16 17

mydata$date <- as.Date(mydata$date)
Error in as.Date.numeric(mydata$date) : 'origin' must be supplied