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Shawn Way

2004-Feb-04 14:31 UTC

[R] Date Time Conversion problems...

At one time (version 1.7), the code below used to work for converting and
extracting based on the Date Time.  In version 1.8.1, something changed I
know, but I cannot for the life of me figure out what...

Data:

UserName,RequestDate,PO,OrderDate,ExpDelivDate,Vendor,Total
"Woody, Jim",12/19/2002,AP15063,1/7/2003,2/10/2003,Ames ,8570
"Harrold, Paul",12/31/2002,AP15083,1/9/2003,1/10/2003,Ryan ,1039.5
"Vo, Hoang",12/27/2002,AP15055,1/6/2003,1/13/2003,TIDEA,1005.36
"Way, Shawn",1/2/2003,AP15043,1/2/2003,1/9/2003,JS   ,1000
"Vo, Hoang",1/7/2003,SO17440,1/8/2003,12/31/2003,USFi-,3705
"Harrold, Paul",1/10/2003,AP15122,1/13/2003,1/14/2003,FishM,65.06

Old Code:

library(lattice)
data <- read.csv("h:\\list3.csv",header=TRUE)
data2 <-
data.frame(Name=data$UserName,Date=data$RequestDate,Vendor=data$Vendor,Costdata$Total)
data2$Date <- strptime(as.character(data2$Date),format="%m/%d/%Y")
start <- strptime(c("1/01/2003"),format="%m/%d/%Y")
end <- strptime(c("12/31/2003"),format="%m/%d/%Y")
data3 <- data2[data2$Date >= start & data2$Date <= end,]
lset(col.whitebg())
xyplot(Cost~as.POSIXct(Date)|Name,data=data3,
       xlab="Date",
       ylab="PO Cost($)",
       ylim=c(0,10000),
       panel= function(x,y){
         a <- mean(y)
         panel.grid(h=-1,v=2)
         panel.xyplot(x,y)
         panel.abline(h=a,col="red")
       }
       )

The error I get is from line 4, 
> data2$Date <-
strptime(as.character(data2$Date),format="%m/%d/%Y")Error in "$<-.data.frame"(`*tmp*`, "Date", value
strptime(as.character(data2$Date),  :
	replacement has 9 rows, data has 230

This used to work for replacing the dates with POSIX values...

Also of interest is the extraction for data3, is this the correct method for
extraction?

What I'm looking at is the spending habits of individuals...

Thanks for your help...

  _____  

"Don't rush me, you rush a miracle, you get a rotten miracle." 
-Miracle Max, The Princess Bride

  _____  

 	Shawn Way, PE	 Tanox, Inc.	
Engineering Manager	 10301 Stella Link	
sway at tanox.com	 Houston, TX 77025

Dirk Eddelbuettel

2004-Feb-04 17:30 UTC

head link

[R] Date Time Conversion problems...

On Wed, Feb 04, 2004 at 08:31:56AM -0600, Shawn Way
wrote:> At one time (version 1.7), the code below used to work for converting and
> extracting based on the Date Time.  In version 1.8.1, something changed I
> know, but I cannot for the life of me figure out what...
> 
> Data:
> 
> UserName,RequestDate,PO,OrderDate,ExpDelivDate,Vendor,Total
> "Woody, Jim",12/19/2002,AP15063,1/7/2003,2/10/2003,Ames ,8570
> "Harrold, Paul",12/31/2002,AP15083,1/9/2003,1/10/2003,Ryan
,1039.5
> "Vo, Hoang",12/27/2002,AP15055,1/6/2003,1/13/2003,TIDEA,1005.36
> "Way, Shawn",1/2/2003,AP15043,1/2/2003,1/9/2003,JS   ,1000
> "Vo, Hoang",1/7/2003,SO17440,1/8/2003,12/31/2003,USFi-,3705
> "Harrold, Paul",1/10/2003,AP15122,1/13/2003,1/14/2003,FishM,65.06
> 
> Old Code:
> 
> library(lattice)
> data <- read.csv("h:\\list3.csv",header=TRUE)
> data2 <-
>
data.frame(Name=data$UserName,Date=data$RequestDate,Vendor=data$Vendor,Cost>
data$Total)
> data2$Date <-
strptime(as.character(data2$Date),format="%m/%d/%Y")
> start <- strptime(c("1/01/2003"),format="%m/%d/%Y")
> end <- strptime(c("12/31/2003"),format="%m/%d/%Y")
> data3 <- data2[data2$Date >= start & data2$Date <= end,]
> lset(col.whitebg())
> xyplot(Cost~as.POSIXct(Date)|Name,data=data3,
>        xlab="Date",
>        ylab="PO Cost($)",
>        ylim=c(0,10000),
>        panel= function(x,y){
>          a <- mean(y)
>          panel.grid(h=-1,v=2)
>          panel.xyplot(x,y)
>          panel.abline(h=a,col="red")
>        }
>        )
> 
> The error I get is from line 4, 
> 
> > data2$Date <-
strptime(as.character(data2$Date),format="%m/%d/%Y")
> Error in "$<-.data.frame"(`*tmp*`, "Date", value
> strptime(as.character(data2$Date),  :
> 	replacement has 9 rows, data has 230
The '9 rows' gives it aways -- it works with an explicit time object
cast:

data2$Date <-
as.POSIXct(strptime(as.character(data2$Date),format="%m/%d/%Y"))
start <-
as.POSIXct(strptime(c("1/01/2003"),format="%m/%d/%Y"))
end <-
as.POSIXct(strptime(c("12/31/2003"),format="%m/%d/%Y"))
> This used to work for replacing the dates with POSIX values...
> 
> Also of interest is the extraction for data3, is this the correct method
for
> extraction?
It works.  A more formal way is in the subsetting and range functions for
the its package.

Dirk

-- 
The relationship between the computed price and reality is as yet unknown.  
                                             -- From the pac(8) manual page

Gabor Grothendieck

2004-Feb-04 17:35 UTC

head link

[R] Date Time Conversion problems...

One uses POSIXct dates in data frames, not POSIXlt 
dates (which is what strptime produces).

To correct this replace:

   strptime(...) with as.POSIXct(strptime(...))

or just add 0, i.e. replace:

   strptime(...) with strptime(...)+0


---

Date:   Wed, 4 Feb 2004 08:31:56 -0600  
From:   Shawn Way <sway at tanox.com>
To:   'r-help at stat.math.ethz.ch' <r-help at stat.math.ethz.ch> 
Subject:   [R] Date Time Conversion problems... 

 
At one time (version 1.7), the code below used to work for converting and
extracting based on the Date Time. In version 1.8.1, something changed I
know, but I cannot for the life of me figure out what...

Data:

UserName,RequestDate,PO,OrderDate,ExpDelivDate,Vendor,Total
"Woody, Jim",12/19/2002,AP15063,1/7/2003,2/10/2003,Ames ,8570
"Harrold, Paul",12/31/2002,AP15083,1/9/2003,1/10/2003,Ryan ,1039.5
"Vo, Hoang",12/27/2002,AP15055,1/6/2003,1/13/2003,TIDEA,1005.36
"Way, Shawn",1/2/2003,AP15043,1/2/2003,1/9/2003,JS ,1000
"Vo, Hoang",1/7/2003,SO17440,1/8/2003,12/31/2003,USFi-,3705
"Harrold, Paul",1/10/2003,AP15122,1/13/2003,1/14/2003,FishM,65.06

Old Code:

library(lattice)
data <- read.csv("h:\\list3.csv",header=TRUE)
data2 <-
data.frame(Name=data$UserName,Date=data$RequestDate,Vendor=data$Vendor,Costdata$Total)
data2$Date <- strptime(as.character(data2$Date),format="%m/%d/%Y")
start <- strptime(c("1/01/2003"),format="%m/%d/%Y")
end <- strptime(c("12/31/2003"),format="%m/%d/%Y")
data3 <- data2[data2$Date >= start & data2$Date <= end,]
lset(col.whitebg())
xyplot(Cost~as.POSIXct(Date)|Name,data=data3,
xlab="Date",
ylab="PO Cost($)",
ylim=c(0,10000),
panel= function(x,y){
a <- mean(y)
panel.grid(h=-1,v=2)
panel.xyplot(x,y)
panel.abline(h=a,col="red")
}
)

The error I get is from line 4, 
> data2$Date <-
strptime(as.character(data2$Date),format="%m/%d/%Y")Error in "$<-.data.frame"(`*tmp*`, "Date", value
strptime(as.character(data2$Date), :
     replacement has 9 rows, data has 230

This used to work for replacing the dates with POSIX values...

Also of interest is the extraction for data3, is this the correct method for
extraction?

What I'm looking at is the spending habits of individuals...

Thanks for your help...

_____ 

"Don't rush me, you rush a miracle, you get a rotten miracle." 
-Miracle Max, The Princess Bride

_____ 

     Shawn Way, PE      Tanox, Inc.     
Engineering Manager      10301 Stella Link     
sway at tanox.com      Houston, TX 77025

Prof Brian Ripley

2004-Feb-04 17:51 UTC

head link

[R] Date Time Conversion problems...

It never worked: there was an undetected error and you got a corrupt data 
frame.  Here is concocted example from 1.7.0
> date <- as.POSIXlt(c(Sys.time(), Sys.time()))
> DF <- data.frame(x=1)
> DF$date <- date
> DFError in data.frame(x = "1", date = c("2004-02-04 17:47:50",
"2004-02-04
...

You cannot add a list of length 9 to a dataframe by

data2$Date <- strptime(as.character(data2$Date),format="%m/%d/%Y")

and now you get a sensible error message.

You need to convert Date to POSIXct before trying to put the object in a
data frame.


On Wed, 4 Feb 2004, Shawn Way wrote:
> At one time (version 1.7), the code below used to work for converting and
> extracting based on the Date Time.  In version 1.8.1, something changed I
> know, but I cannot for the life of me figure out what...
> 
> Data:
> 
> UserName,RequestDate,PO,OrderDate,ExpDelivDate,Vendor,Total
> "Woody, Jim",12/19/2002,AP15063,1/7/2003,2/10/2003,Ames ,8570
> "Harrold, Paul",12/31/2002,AP15083,1/9/2003,1/10/2003,Ryan
,1039.5
> "Vo, Hoang",12/27/2002,AP15055,1/6/2003,1/13/2003,TIDEA,1005.36
> "Way, Shawn",1/2/2003,AP15043,1/2/2003,1/9/2003,JS   ,1000
> "Vo, Hoang",1/7/2003,SO17440,1/8/2003,12/31/2003,USFi-,3705
> "Harrold, Paul",1/10/2003,AP15122,1/13/2003,1/14/2003,FishM,65.06
> 
> Old Code:
> 
> library(lattice)
> data <- read.csv("h:\\list3.csv",header=TRUE)
> data2 <-
>
data.frame(Name=data$UserName,Date=data$RequestDate,Vendor=data$Vendor,Cost>
data$Total)
> data2$Date <-
strptime(as.character(data2$Date),format="%m/%d/%Y")
> start <- strptime(c("1/01/2003"),format="%m/%d/%Y")
> end <- strptime(c("12/31/2003"),format="%m/%d/%Y")
> data3 <- data2[data2$Date >= start & data2$Date <= end,]
> lset(col.whitebg())
> xyplot(Cost~as.POSIXct(Date)|Name,data=data3,
>        xlab="Date",
>        ylab="PO Cost($)",
>        ylim=c(0,10000),
>        panel= function(x,y){
>          a <- mean(y)
>          panel.grid(h=-1,v=2)
>          panel.xyplot(x,y)
>          panel.abline(h=a,col="red")
>        }
>        )
> 
> The error I get is from line 4, 
> 
> > data2$Date <-
strptime(as.character(data2$Date),format="%m/%d/%Y")
> Error in "$<-.data.frame"(`*tmp*`, "Date", value
> strptime(as.character(data2$Date),  :
> 	replacement has 9 rows, data has 230
> 
> This used to work for replacing the dates with POSIX values...

-- 
Brian D. Ripley,                  ripley at stats.ox.ac.uk
Professor of Applied Statistics,  http://www.stats.ox.ac.uk/~ripley/
University of Oxford,             Tel:  +44 1865 272861 (self)
1 South Parks Road,                     +44 1865 272866 (PA)
Oxford OX1 3TG, UK                Fax:  +44 1865 272595

Patrick Connolly

2004-Feb-04 20:35 UTC

head link

[R] Date Time Conversion problems...

On Wed, 04-Feb-2004 at 08:31AM -0600, Shawn Way wrote:

|> At one time (version 1.7), the code below used to work for converting and
|> extracting based on the Date Time.  In version 1.8.1, something changed I
|> know, but I cannot for the life of me figure out what...


[...]

|> 
|> The error I get is from line 4, 
|> 
|> > data2$Date <-
strptime(as.character(data2$Date),format="%m/%d/%Y")
|> Error in "$<-.data.frame"(`*tmp*`, "Date", value
|> strptime(as.character(data2$Date),  :
|> 	replacement has 9 rows, data has 230
|> 
|> This used to work for replacing the dates with POSIX values...

Try:

data2$Date <-
as.POSIXct(strptime(as.character(data2$Date),format="%m/%d/%Y"))

You'll find that it prints the date labels more usefully in 1.8.1

HTH

-- 
Patrick Connolly
HortResearch
Mt Albert
Auckland
New Zealand 
Ph: +64-9 815 4200 x 7188
~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~
I have the world`s largest collection of seashells. I keep it on all
the beaches of the world ... Perhaps you`ve seen it.  ---Steven Wright 
~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~

Petr Pikal

2004-Feb-06 09:18 UTC

head link

[R] Date Time Conversion problems...

Hi

On 4 Feb 2004 at 8:31, Shawn Way wrote:
> At one time (version 1.7), the code below used to work for converting
> and extracting based on the Date Time.  In version 1.8.1, something
> changed I know, but I cannot for the life of me figure out what...
> 
> Data:
> 
> UserName,RequestDate,PO,OrderDate,ExpDelivDate,Vendor,Total
> "Woody, Jim",12/19/2002,AP15063,1/7/2003,2/10/2003,Ames ,8570
> "Harrold, Paul",12/31/2002,AP15083,1/9/2003,1/10/2003,Ryan
,1039.5
> "Vo, Hoang",12/27/2002,AP15055,1/6/2003,1/13/2003,TIDEA,1005.36
"Way,
> Shawn",1/2/2003,AP15043,1/2/2003,1/9/2003,JS   ,1000 "Vo,
> Hoang",1/7/2003,SO17440,1/8/2003,12/31/2003,USFi-,3705 "Harrold,
> Paul",1/10/2003,AP15122,1/13/2003,1/14/2003,FishM,65.06
> 
> Old Code:
> 
> library(lattice)
> data <- read.csv("h:\\list3.csv",header=TRUE)
> data2 <-
> data.frame(Name=data$UserName,Date=data$RequestDate,Vendor=data$Vendor
> ,Cost= data$Total) data2$Date <-
> strptime(as.character(data2$Date),format="%m/%d/%Y") start <-
> strptime(c("1/01/2003"),format="%m/%d/%Y") end <-
> strptime(c("12/31/2003"),format="%m/%d/%Y") data3 <-
data2[data2$Date
> >= start & data2$Date <= end,] lset(col.whitebg())
> xyplot(Cost~as.POSIXct(Date)|Name,data=data3,
>        xlab="Date",
>        ylab="PO Cost($)",
>        ylim=c(0,10000),
>        panel= function(x,y){
>          a <- mean(y)
>          panel.grid(h=-1,v=2)
>          panel.xyplot(x,y)
>          panel.abline(h=a,col="red")
>        }
>        )
> 
> The error I get is from line 4, 
> 
> > data2$Date <-
strptime(as.character(data2$Date),format="%m/%d/%Y")
> Error in "$<-.data.frame"(`*tmp*`, "Date", value
> strptime(as.character(data2$Date),  :
>  replacement has 9 rows, data has 230
most probably you have POSIXlt format

try

length(strptime(as.character(data2$Date),format="%m/%d/%Y"))
should result 9

you have to change to POSIXct through as.POSIXct

andd you than get lengthof your date vector to be correct.

Cheers
Petr


> 
> This used to work for replacing the dates with POSIX values...
> 
> Also of interest is the extraction for data3, is this the correct
> method for extraction?
> 
> What I'm looking at is the spending habits of individuals...
> 
> Thanks for your help...
> 
>   _____  
> 
> "Don't rush me, you rush a miracle, you get a rotten
miracle."
> -Miracle Max, The Princess Bride
> 
>   _____  
> 
>   Shawn Way, PE	 Tanox, Inc.	
> Engineering Manager	 10301 Stella Link	
> sway at tanox.com	 Houston, TX 77025
> 
> ______________________________________________
> R-help at stat.math.ethz.ch mailing list
> https://www.stat.math.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide!
> http://www.R-project.org/posting-guide.html
Petr Pikal
petr.pikal at precheza.cz

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