[R] Irregular Time Series: zoo & its: Pros & Cons

From: David James <djames_at_frontierassoc.com>
Date: Fri 26 Aug 2005 - 03:51:10 EST

Hello,

I'm working with irregular time series data. What do you all think about the strengths and weaknesses of the "zoo" and "its" packages?

I've installed and skimmed the documentation on both packages. I was hoping to get a little guidance from the user community before proceeding further.

In case anyone is interested in my particular problem: I'm looking at some (surface) temperature data from NOAA: http:// cdo.ncdc.noaa.gov/ulcd/ULCD
It is (irregular) time series format. The NOAA data reports year, month, date, hour, and minute. I want to group the data into hourly chunks. However, sometimes there are multiple observation per hour -- i.e an observation at 3:45 and 3:56. Also, sometimes a particular hour may be missing altogether. I need to clean up the data so that each hour has one and only one data point.

I'm relatively new to R, but I think I'm getting a hold on it pretty well so far. I used to do a lot with MATLAB, and there seem to be many parallels between it and R. I have background in public policy and econometrics.

Thanks,
David

On Aug 25, 2005, at 12:29 PM, Mathieu Drapeau wrote:

> Hi,
> I just installed ROracle and RDBI. The connection to the database
> seems
> to work also. My problem is when I am selection rows that really exist
> in the database, it is returning nothing. Where should I look to see
> what could be my problem?
>
> Thank you very much,
> Mathieu
>
>
>> drv <- dbDriver("Oracle")
>> summary(drv, verbose=TRUE)
>>
> <OraDriver:(6721)>
> Driver name: Oracle (ProC/C++)
> Max connections: 10
> Conn. processed: 8
> Default records per fetch: 500
> Oracle R/S client version: 0.5-4
> RS-DBI version: 0.1-9
> Open connections: 2
> 1 <OraConnection:(6721,0)>
> 2 <OraConnection:(6721,7)>
>
>>
>> conn <- dbConnect(drv, "mathieu/toto@MYDB")
>> summary(conn, verbose=TRUE) <OraConnection:(6721,7)>
>>
> User: mathieu
> Dbname: MYDB
> Oracle Server version:
>
>>
>> rs <- dbSendQuery(conn, statement = paste("select * from cat"))
>> summary(rs, verbose=TRUE)
>>
> <OraResult:(6721,7,2)>
> Statement: select * from cat
> Has completed? no
> Affected rows: 0
> Rows fetched: -1
> Fields:
> name Sclass type len precision scale isVarLength nullOK
> 1 TABLE_NAME character VARCHAR2 30 0 0 TRUE FALSE
> 2 TABLE_TYPE character VARCHAR2 11 0 0 TRUE TRUE
>
>>
>> myContent <- fetch(rs, n = -1)
>> myContent
>>
> [1] TABLE_NAME TABLE_TYPE
> <0 rows> (or 0-length row.names)
>
>> summary(myContent, verbose=TRUE)
>>
> TABLE_NAME TABLE_TYPE
> Length:0 Length:0
> Class :character Class :character
> Mode :character Mode :character
>
>> summary(rs, verbose=TRUE)
>>
> <OraResult:(6721,7,2)>
> Statement: select * from cat
> Has completed? yes
> Affected rows: 0
> Rows fetched: -1
> Fields:
> name Sclass type len precision scale isVarLength nullOK
> 1 TABLE_NAME character VARCHAR2 30 0 0 TRUE FALSE
> 2 TABLE_TYPE character VARCHAR2 11 0 0 TRUE TRUE
>
> ______________________________________________
> R-help@stat.math.ethz.ch mailing list
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> PLEASE do read the posting guide! http://www.R-project.org/posting-
> guide.html
>



R-help@stat.math.ethz.ch mailing list
https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html Received on Fri Aug 26 03:56:52 2005

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