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algotr8der

2012-Aug-01 14:21 UTC

[R] as.date: do not know how to convert 'test[1]' to class "Date"

I have an object, which I pull in from a csv file here  
http://r.789695.n4.nabble.com/file/n4638691/jan_2011.csv jan_2011.csv 

mydata <- read.csv("jan_2011.csv", header=TRUE, sep=",")
> head(mydata)  Delivery.Date Hour.Ending Repeated.Hour.Flag Settlement.Point
Settlement.Point.Price
1    01/01/2011       01:00                  N        HB_BUSAVG                 
25.18
2    01/01/2011       01:00                  N       HB_HOUSTON                 
25.36
3    01/01/2011       01:00                  N        HB_HUBAVG                 
25.07
4    01/01/2011       01:00                  N         HB_NORTH                 
25.33
5    01/01/2011       01:00                  N         HB_SOUTH                 
25.12
6    01/01/2011       01:00                  N          HB_WEST                 
24.49
> str(mydata)'data.frame':	10416 obs. of  5 variables:
 $ Delivery.Date         : Factor w/ 31 levels
"01/01/2011","01/02/2011",..:
1 1 1 1 1 1 1 1 1 1 ...
 $ Hour.Ending           : Factor w/ 24 levels
"01:00","02:00",..: 1 1 1 1 1
1 1 1 1 1 ...
 $ Repeated.Hour.Flag    : Factor w/ 1 level "N": 1 1 1 1 1 1 1 1 1 1
...
 $ Settlement.Point      : Factor w/ 14 levels
"HB_BUSAVG","HB_HOUSTON",..:
1 2 3 4 5 6 7 8 9 10 ...
 $ Settlement.Point.Price: num  25.2 25.4 25.1 25.3 25.1 ...

I want to convert the Delivery.Date field to a date object. I tried various
attempts but failed with the following:
> as.Date(mydata[1], "%m/%d/%Y")Error in as.Date.default(ercot[1], "%m/%d/%Y") : 
  do not know how to convert 'ercot[1]' to class "Date"

I even tried to save the first column to a separate object and tried the
same but got the same result.  At this point I'm not sure how to move
forward. Appreciate the help.





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Ricardogg

2012-Aug-01 14:38 UTC

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[R] as.date: do not know how to convert 'mydata[1]' to class "Date"

For me it owrks when i write it like:

as.Date(paste(mydata$Delivery.Date), "%m/%d/%Y") 

Hope it works,

Regards,

Ricardo



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algotr8der

2012-Aug-01 15:58 UTC

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[R] as.date: do not know how to convert 'mydata[1]' to class "Date"

Thank you Ricardogg and Arun. I don't know how I missed that. Too many
sleepless nights perhaps. Thank you. 



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R. Michael Weylandt

2012-Aug-01 22:34 UTC

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[R] as.date: do not know how to convert 'test[1]' to class "Date"

Please don't post files to nabble in the future -- when Nabble removes
them, we then have a broken link in the real archives: dput() is much
preferred way to send data.

Anyways:

# mydata <-
read.csv("http://r.789695.n4.nabble.com/file/n4638691/jan_2011.csv")
#
# dput(head(mydata, 15))

structure(list(Delivery.Date = structure(c(1L, 1L, 1L, 1L, 1L,
1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L), .Label = c("01/01/2011",
"01/02/2011", "01/03/2011", "01/04/2011",
"01/05/2011", "01/06/2011",
"01/07/2011", "01/08/2011", "01/09/2011",
"01/10/2011", "01/11/2011",
"01/12/2011", "01/13/2011", "01/14/2011",
"01/15/2011", "01/16/2011",
"01/17/2011", "01/18/2011", "01/19/2011",
"01/20/2011", "01/21/2011",
"01/22/2011", "01/23/2011", "01/24/2011",
"01/25/2011", "01/26/2011",
"01/27/2011", "01/28/2011", "01/29/2011",
"01/30/2011", "01/31/2011"
), class = "factor"), Hour.Ending = structure(c(1L, 1L, 1L, 1L,
1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 2L), .Label = c("01:00",
"02:00", "03:00", "04:00", "05:00",
"06:00", "07:00", "08:00",
"09:00", "10:00", "11:00", "12:00",
"13:00", "14:00", "15:00",
"16:00", "17:00", "18:00", "19:00",
"20:00", "21:00", "22:00",
"23:00", "24:00"), class = "factor"),
Repeated.Hour.Flag = structure(c(1L,
1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L), .Label = "N",
class = "factor"),
    Settlement.Point = structure(c(1L, 2L, 3L, 4L, 5L, 6L, 7L,
    8L, 9L, 10L, 11L, 12L, 13L, 14L, 1L), .Label = c("HB_BUSAVG",
    "HB_HOUSTON", "HB_HUBAVG", "HB_NORTH",
"HB_SOUTH", "HB_WEST",
    "LZ_AEN", "LZ_CPS", "LZ_HOUSTON",
"LZ_LCRA", "LZ_NORTH",
    "LZ_RAYBN", "LZ_SOUTH", "LZ_WEST"), class =
"factor"),
Settlement.Point.Price = c(25.18,
    25.36, 25.07, 25.33, 25.12, 24.49, 25.2, 25.12, 25.41, 25.15,
    25.32, 25.32, 25.1, 25.07, 23.84)), .Names = c("Delivery.Date",
"Hour.Ending", "Repeated.Hour.Flag",
"Settlement.Point",
"Settlement.Point.Price"
), row.names = c(NA, 15L), class = "data.frame")

mydata[,1] <- as.Date(mydata[,1], format = "%m/%d/%Y")

works just fine for me. Note that you were missing a column.

On Wed, Aug 1, 2012 at 9:21 AM, algotr8der <algotr8der at gmail.com>
wrote:> I have an object, which I pull in from a csv file here
> http://r.789695.n4.nabble.com/file/n4638691/jan_2011.csv jan_2011.csv
>
> mydata <- read.csv("jan_2011.csv", header=TRUE,
sep=",")
>
>> head(mydata)
>   Delivery.Date Hour.Ending Repeated.Hour.Flag Settlement.Point
> Settlement.Point.Price
> 1    01/01/2011       01:00                  N        HB_BUSAVG
> 25.18
> 2    01/01/2011       01:00                  N       HB_HOUSTON
> 25.36
> 3    01/01/2011       01:00                  N        HB_HUBAVG
> 25.07
> 4    01/01/2011       01:00                  N         HB_NORTH
> 25.33
> 5    01/01/2011       01:00                  N         HB_SOUTH
> 25.12
> 6    01/01/2011       01:00                  N          HB_WEST
> 24.49
>
>> str(mydata)
> 'data.frame':   10416 obs. of  5 variables:
>  $ Delivery.Date         : Factor w/ 31 levels
"01/01/2011","01/02/2011",..:
> 1 1 1 1 1 1 1 1 1 1 ...
>  $ Hour.Ending           : Factor w/ 24 levels
"01:00","02:00",..: 1 1 1 1 1
> 1 1 1 1 1 ...
>  $ Repeated.Hour.Flag    : Factor w/ 1 level "N": 1 1 1 1 1 1 1 1
1 1 ...
>  $ Settlement.Point      : Factor w/ 14 levels
"HB_BUSAVG","HB_HOUSTON",..:
> 1 2 3 4 5 6 7 8 9 10 ...
>  $ Settlement.Point.Price: num  25.2 25.4 25.1 25.3 25.1 ...
>
> I want to convert the Delivery.Date field to a date object. I tried various
> attempts but failed with the following:
>
>> as.Date(mydata[1], "%m/%d/%Y")
> Error in as.Date.default(ercot[1], "%m/%d/%Y") :
>   do not know how to convert 'ercot[1]' to class "Date"
No idea where this "ercot" thing comes from.

Best,
Michael
>
> I even tried to save the first column to a separate object and tried the
> same but got the same result.  At this point I'm not sure how to move
> forward. Appreciate the help.
>
>
>
>
>
> --
> View this message in context:
http://r.789695.n4.nabble.com/as-date-do-not-know-how-to-convert-test-1-to-class-Date-tp4638691.html
> Sent from the R help mailing list archive at Nabble.com.
>
> ______________________________________________
> R-help at r-project.org mailing list
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide
http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.

Rui Barradas

2012-Aug-01 22:40 UTC

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[R] as.date: do not know how to convert 'test[1]' to class "Date"

Hello,

Try reading the data file with stringsAsFactors = FALSE, like this you 
don't have character vectors, you have factors, which are coded as 
consecutive integers 1, 2, etc.

?read.table
?read.csv

See in particular the argument above, stringsAsFactors

Hope this helps,

Rui Barradas

Em 01-08-2012 15:21, algotr8der escreveu:> I have an object, which I pull in from a csv file here
> http://r.789695.n4.nabble.com/file/n4638691/jan_2011.csv jan_2011.csv
>
> mydata <- read.csv("jan_2011.csv", header=TRUE,
sep=",")
>
>> head(mydata)
>    Delivery.Date Hour.Ending Repeated.Hour.Flag Settlement.Point
> Settlement.Point.Price
> 1    01/01/2011       01:00                  N        HB_BUSAVG
> 25.18
> 2    01/01/2011       01:00                  N       HB_HOUSTON
> 25.36
> 3    01/01/2011       01:00                  N        HB_HUBAVG
> 25.07
> 4    01/01/2011       01:00                  N         HB_NORTH
> 25.33
> 5    01/01/2011       01:00                  N         HB_SOUTH
> 25.12
> 6    01/01/2011       01:00                  N          HB_WEST
> 24.49
>
>> str(mydata)
> 'data.frame':	10416 obs. of  5 variables:
>   $ Delivery.Date         : Factor w/ 31 levels
"01/01/2011","01/02/2011",..:
> 1 1 1 1 1 1 1 1 1 1 ...
>   $ Hour.Ending           : Factor w/ 24 levels
"01:00","02:00",..: 1 1 1 1 1
> 1 1 1 1 1 ...
>   $ Repeated.Hour.Flag    : Factor w/ 1 level "N": 1 1 1 1 1 1 1
1 1 1 ...
>   $ Settlement.Point      : Factor w/ 14 levels
"HB_BUSAVG","HB_HOUSTON",..:
> 1 2 3 4 5 6 7 8 9 10 ...
>   $ Settlement.Point.Price: num  25.2 25.4 25.1 25.3 25.1 ...
>
> I want to convert the Delivery.Date field to a date object. I tried various
> attempts but failed with the following:
>
>> as.Date(mydata[1], "%m/%d/%Y")
> Error in as.Date.default(ercot[1], "%m/%d/%Y") :
>    do not know how to convert 'ercot[1]' to class "Date"
>
> I even tried to save the first column to a separate object and tried the
> same but got the same result.  At this point I'm not sure how to move
> forward. Appreciate the help.
>
>
>
>
>
> --
> View this message in context:
http://r.789695.n4.nabble.com/as-date-do-not-know-how-to-convert-test-1-to-class-Date-tp4638691.html
> Sent from the R help mailing list archive at Nabble.com.
>
> ______________________________________________
> R-help at r-project.org mailing list
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide
http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.

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