[R] A question about POSIXct

[Michael Sumner]

Hello,

It seems that "danish" is a numeric vector with attributes attached - 
the attribute vector is POSIXct and is the same length as danish.

You can create this from a data frame like this:

 x <- data.frame(Date = ISOdate(2007, 5, 1:10), Value = rnorm(10))
str(x)
'data.frame':   10 obs. of  2 variables:
 $ Date :'POSIXct', format: chr  "2007-05-01 12:00:00" "2007-05-02 
12:00:00" "2007-05-03 12:00:00" "2007-05-04 12:00:00" ...
 $ Value: num   1.891  0.741 -0.368  1.701 -0.660 ...

 xx <- x$Value
attr(xx, "times") <- x$Date
str(xx)
 atomic [1:10]  0.0414 -0.7124 -1.2976  0.3101  0.4343 ...
 - attr(*, "times")='POSIXct', format: chr [1:10] "2007-05-01 12:00:00" 
"2007-05-02 12:00:00" "2007-05-03 12:00:00" "2007-05-04 12:00:00" ...


HTH

Cheers, Mike.

> Dear List:
>
> I have a simple two-column data set in .csv format, with the first column
> being the date and second column being some value.  I use read.csv() to
> import the data as follows:
>
>
>
> x <- read.csv("myfile.csv",header=T, dec=".", colClasses=c(Date="POSIXct"))
>
>
>
> The structure of x is:
>
>
>
> > str(x)
>
> `data.frame':   2959 obs. of  2 variables:
>
>  $ Date:'POSIXct', format: chr  "1998-01-01" "1998-01-01" "1998-01-01"
> "1998-01-01" ...
>
>  $ Value: num  0.07379 0.07181 0.01555 0.00630 0.00688 ...
>
>
>
> This is not what I want.  Instead, I want the structure to be the same as
> that of the following data set:
>
>
>
> > str(danish)
>
>  atomic [1:2167] 1.68 2.09 1.73 1.78 4.61 ...
>
>  - attr(*, "times")='POSIXct', format: chr [1:2167] "1980-01-02 18:00:00"
> "1980-01-03 18:00:00" "1980-01-04 18:00:00" "1980-01-06 18:00:00" ...
>
>
>
> "danish" is a data set that the package "evir" comes with.
>
>
> Any help would be appreciated.
>
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>
>