Re: [R] Question regarding sqldf

2009-07-31 Thread Rizzo . Michael
My sqldf package was already updated. The result from the example you
ran is also missing 2 of the five days so something still isn't working
correctly.




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  |milton ruser milton.ru...@gmail.com
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  |Michael Rizzo/RTP/USEPA/u...@epa 
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  |r-help@r-project.org 
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| Date:  |
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  |07/30/2009 05:56 PM  
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  |Re: [R] Question regarding sqldf 
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How about update R/sqldf?

 require(sqlf)
Loading required package: sqlf
Warning message:
In library(package, lib.loc = lib.loc, character.only = TRUE,
logical.return = TRUE,  :
  there is no package called 'sqlf'

 testframe-data.frame(sdate=rep(paste
+ (day,1:5,sep=),each=5),bext=runif(25,1,100),otherstuff=runif
+ (25,45,60),stuff=runif(25,3,25))


 maxdays-sqldf(select distinct * from testframe group by sdate having
bext=max(bext))
 maxdays
  sdate bext otherstuff stuff
1  day1 77.20252   51.77503 12.045835
2  day2 91.37352   50.07259  4.468679
3  day5 74.29047   58.58456 10.027444



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[R] Question regarding sqldf

2009-07-30 Thread Rizzo . Michael

Hello,

I am having a problem using sqldf.  I'm trying to choose a subset of
observations from a data set based on the date and maximum value of a
variable by date.

Here is the code I am using:

test-sqldf(select distinct * from bextuse group by sdate having
bext=max(bext),method=raw);

The result I get back is a data frame with 0 rows and 0 columns.  I have
tried the code in another program that utilizes SQL, and I retrieve the
14 rows I was expecting to get.
I looked at the SQLite information on the web, and it mentions that the
having clause can be used to select observations from grouped data
using aggregating functions.

Any help or advice is greatly appreciated.

__
R-help@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.


Re: [R] Question regarding sqldf

2009-07-30 Thread Rizzo . Michael
Here is a test data frame:

 testframe-data.frame(sdate=rep(paste
(day,1:5,sep=),each=5),bext=runif(25,1,100),otherstuff=runif
(25,45,60),stuff=runif(25,3,25))
 testframe
   sdate  bext otherstuff stuff
1   day1 37.863859   49.19816 10.036211
2   day1 58.557049   59.23145 21.793954
3   day1 70.345462   48.82313 24.630742
4   day1  1.245913   57.70718 14.131270
5   day1 40.170634   50.38963 21.420328
6   day2 36.126846   51.97043 22.815169
7   day2 95.801896   53.30061 13.540535
8   day2 19.959486   50.46775  9.403084
9   day2  5.772996   55.14082 17.137113
10  day2 77.956966   51.44969 13.448527
11  day3  6.743810   54.49836 17.650795
12  day3 60.758896   55.35407  5.005359
13  day3 86.924873   57.74122  8.691572
14  day3 91.933544   48.17538  8.559737
15  day3 23.627126   59.28906  4.766172
16  day4 76.200158   55.78072 19.493428
17  day4 67.809049   51.06784  7.116428
18  day4 70.309643   54.38067 10.736461
19  day4 91.152166   58.39768 23.199943
20  day4 30.358417   54.16645 24.153823
21  day5 64.064953   58.31813 19.856882
22  day5 49.220106   48.49721 16.615940
23  day5 21.554696   47.03421  3.585458
24  day5 30.227874   55.51724 14.435731
25  day5 51.518716   54.31445 20.837326

If I run the following sqldf statement:

 maxdays-sqldf(select distinct * from testframe group by sdate having
bext=max(bext))

I get:

 maxdays
data frame with 0 columns and 0 rows

I want to get the entire observation for each day where bext is the
maximum for the day.



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| From:  |
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  |milton ruser milton.ru...@gmail.com
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| To:|
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  |Michael Rizzo/RTP/USEPA/u...@epa 
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| Cc:|
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  |r-help@r-project.org 
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| Date:  |
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  |07/30/2009 03:03 PM  
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| Subject:   |
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  |Re: [R] Question regarding sqldf 
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Hi Rizzi,

how about a reproducible example/data.frame?

:-)
milton

On Thu, Jul 30, 2009 at 1:46 PM, rizzo.mich...@epamail.epa.gov wrote:

  Hello,

  I am having a problem using sqldf.  I'm trying to choose a subset of
  observations from a data set based on the date and maximum value of a
  variable by date.

  Here is the code I am using:

  test-sqldf(select distinct * from bextuse group by sdate having
  bext=max(bext),method=raw);

  The result I get back is a data frame with 0 rows and 0 columns.  I
  have
  tried the code in another program that utilizes SQL, and I retrieve
  the
  14 rows I was expecting to get.
  I looked at the SQLite information on the web, and it mentions that
  the
  having clause can be used to select observations from grouped data
  using aggregating functions.

  Any help or advice is greatly appreciated.

  __
  R-help@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, 

[R] Does the labpt object in the Polygons-class represent the centroid of the polygon

2009-02-05 Thread Rizzo . Michael

Hello,

I need to calculate the centroids of some spatial polygons that I have
placed into a Polygons-class object.  Is the labeling point in the
Polygons-class the centroid of the polygon?

Thank you for your help.

__
R-help@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.