Re: [R] subset arg in (modified) evalq

2007-05-18 Thread Gabor Grothendieck
Try this:

   with(subset(data, x  0), summary(y + z))


On 5/18/07, Vadim Ogranovich [EMAIL PROTECTED] wrote:
 Hi,

 When using evalq to evaluate expressions within a say data.frame context I 
 often wish there was a 'subset' argument, much like in lm() or any ather 
 advanced regression model. I would be grateful for a tip how to do this.

 Here is an illustration of what I want:

 n - 100
 data - data.frame(x=rnorm(n), y=rnorm(y), z=rnorm(z))

 # this works
 evalq({ i - 0x; summary(y[i] + z[i]) }, data)

 # I want to do the above w/o explicit subscripting, e.g.
 myevalq(summary(y + z), subset=0x, data)

 Thanks,
 Vadim

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Re: [R] subset arg in (modified) evalq

2007-05-18 Thread Gabor Grothendieck
I would check your performance assumption with an actual test before
concluding such but at any rate subset does have a select argument. See
?subset

On 5/18/07, Vadim Ogranovich [EMAIL PROTECTED] wrote:
 Thanks Gabor!  This does exactly what I wanted.

 One follow-up question, how to extract the var names, in this case y, z,
 from the expression? The subset function creates a new object and this may
 be expensive when the data has a lot of irrelevant collumns. So I thougth
 that I could reduce this to the columns I actually need.

 Thanks,
 Vadim



 - Original Message -
 From: Gabor Grothendieck [EMAIL PROTECTED]
 To: Vadim Ogranovich [EMAIL PROTECTED]
 Cc: r-help@stat.math.ethz.ch
 Sent: Friday, May 18, 2007 9:19:49 AM (GMT-0600) America/Chicago
 Subject: Re: [R] subset arg in (modified) evalq

 Try this:

with(subset(data, x  0), summary(y + z))


 On 5/18/07, Vadim Ogranovich [EMAIL PROTECTED] wrote:
  Hi,
 
  When using evalq to evaluate expressions within a say data.frame context I
 often wish there was a 'subset' argument, much like in lm() or any ather
 advanced regression model. I would be grateful for a tip how to do this.
 
  Here is an illustration of what I want:
 
  n - 100
  data - data.frame(x=rnorm(n), y=rnorm(y), z=rnorm(z))
 
  # this works
  evalq({ i - 0x; summary(y[i] + z[i]) }, data)
 
  # I want to do the above w/o explicit subscripting, e.g.
  myevalq(summary(y + z), subset=0x, data)
 
  Thanks,
  Vadim
 
 [[alternative HTML version deleted]]
 
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  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
  and provide commented, minimal, self-contained, reproducible code.
 


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Re: [R] subset arg in (modified) evalq

2007-05-18 Thread Vadim Ogranovich
Thanks Gabor! This does exactly what I wanted. 

One follow-up question, how to extract the var names, in this case y, z, from 
the expression? The subset function creates a new object and this may be 
expensive when the data has a lot of irrelevant collumns. So I thougth that I 
could reduce this to the columns I actually need. 

Thanks, 
Vadim 


- Original Message - 
From: Gabor Grothendieck [EMAIL PROTECTED] 
To: Vadim Ogranovich [EMAIL PROTECTED] 
Cc: r-help@stat.math.ethz.ch 
Sent: Friday, May 18, 2007 9:19:49 AM (GMT-0600) America/Chicago 
Subject: Re: [R] subset arg in (modified) evalq 

Try this: 

with(subset(data, x  0), summary(y + z)) 


On 5/18/07, Vadim Ogranovich [EMAIL PROTECTED] wrote: 
 Hi, 
 
 When using evalq to evaluate expressions within a say data.frame context I 
 often wish there was a 'subset' argument, much like in lm() or any ather 
 advanced regression model. I would be grateful for a tip how to do this. 
 
 Here is an illustration of what I want: 
 
 n - 100 
 data - data.frame(x=rnorm(n), y=rnorm(y), z=rnorm(z)) 
 
 # this works 
 evalq({ i - 0x; summary(y[i] + z[i]) }, data) 
 
 # I want to do the above w/o explicit subscripting, e.g. 
 myevalq(summary(y + z), subset=0x, data) 
 
 Thanks, 
 Vadim 
 
 [[alternative HTML version deleted]] 
 
 __ 
 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 
 and provide commented, minimal, self-contained, reproducible code. 
 

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Re: [R] subset arg in (modified) evalq

2007-05-18 Thread Vadim Ogranovich
Sorry, I didn't explain myself clear enough. I knew about the select arg in 
subset(). My question was, given the expression expression(summary(x+y)), how 
to extract all names that will be looked up during its evaluation. 

As to checking performance assumptions, you are right, in most cases the 
overhead is negligible, but sometimes I work with really big data sets. 

Thanks a lot for your help, 
Vadim 


- Original Message - 
From:  Gabor Grothendieck   ggrothendieck @ gmail .com 
To:  Vadim Ogranovich   vogranovich @ jumptrading .com 
Cc: r-help @stat.math. ethz .ch 
Sent: Friday, May 18, 2007 9:53:26 AM ( GMT-0600 ) America/Chicago 
Subject: Re: [R] subset arg in (modified) evalq 

I would check your performance assumption with an actual test before 
concluding such but at any rate subset does have a select argument. See 
?subset 

On 5/18/07, Vadim Ogranovich  vogranovich @ jumptrading .com wrote: 
 Thanks Gabor ! This does exactly what I wanted. 
 
 One follow-up question, how to extract the var names, in this case y, z, 
 from the expression? The subset function creates a new object and this may 
 be expensive when the data has a lot of irrelevant collumns . So I thougth 
 that I could reduce this to the columns I actually need. 
 
 Thanks, 
 Vadim 
 
 
 
 - Original Message - 
 From:  Gabor Grothendieck   ggrothendieck @ gmail .com 
 To:  Vadim Ogranovich   vogranovich @ jumptrading .com 
 Cc: r-help @stat.math. ethz .ch 
 Sent: Friday, May 18, 2007 9:19:49 AM ( GMT-0600 ) America/Chicago 
 Subject: Re: [R] subset arg in (modified) evalq 
 
 Try this: 
 
 with(subset(data, x  0), summary(y + z)) 
 
 
 On 5/18/07, Vadim Ogranovich  vogranovich @ jumptrading .com wrote: 
  Hi, 
  
  When using evalq to evaluate expressions within a say data.frame context I 
 often wish there was a 'subset' argument, much like in lm () or any ather 
 advanced regression model. I would be grateful for a tip how to do this. 
  
  Here is an illustration of what I want: 
  
  n - 100 
  data - data.frame(x= rnorm (n), y= rnorm (y), z= rnorm (z)) 
  
  # this works 
  evalq ({ i - 0x; summary(y[i] + z[i]) }, data) 
  
  # I want to do the above w/o explicit subscripting , e.g. 
  myevalq (summary(y + z), subset=0x, data) 
  
  Thanks, 
  Vadim 
  
  [[alternative HTML version deleted]] 
  
  __ 
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  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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Re: [R] subset arg in (modified) evalq

2007-05-18 Thread Gabor Grothendieck
Try this:

e - quote(summary(y + z))
all.vars(e)


On 5/18/07, Vadim Ogranovich [EMAIL PROTECTED] wrote:
 Sorry, I didn't explain myself clear enough. I knew about the select arg in
 subset(). My question was, given the expression expression(summary(x+y)),
 how to extract all names that will be looked up during its evaluation.

 As to checking performance assumptions, you are right, in most cases the
 overhead is negligible, but sometimes I work with really big data sets.

 Thanks a lot for your help,
 Vadim


 - Original Message -
 From: Gabor Grothendieck [EMAIL PROTECTED]
 To: Vadim Ogranovich [EMAIL PROTECTED]
 Cc: r-help@stat.math.ethz.ch
 Sent: Friday, May 18, 2007 9:53:26 AM (GMT-0600) America/Chicago
 Subject: Re: [R] subset arg in (modified) evalq

 I would check your performance assumption with an actual test before
 concluding such but at any rate subset does have a select argument. See
 ?subset

 On 5/18/07, Vadim Ogranovich [EMAIL PROTECTED] wrote:
  Thanks Gabor!  This does exactly what I wanted.
 
  One follow-up question, how to extract the var names, in this case y, z,
  from the expression? The subset function creates a new object and this may
  be expensive when the data has a lot of irrelevant collumns. So I thougth
  that I could reduce this to the columns I actually need.
 
  Thanks,
  Vadim
 
 
 
  - Original Message -
  From: Gabor Grothendieck [EMAIL PROTECTED]
  To: Vadim Ogranovich [EMAIL PROTECTED]
  Cc: r-help@stat.math.ethz.ch
  Sent: Friday, May 18, 2007 9:19:49 AM (GMT-0600) America/Chicago
  Subject: Re: [R] subset arg in (modified) evalq
 
  Try this:
 
 with(subset(data, x  0), summary(y + z))
 
 
  On 5/18/07, Vadim Ogranovich [EMAIL PROTECTED] wrote:
   Hi,
  
   When using evalq to evaluate expressions within a say data.frame context
 I
  often wish there was a 'subset' argument, much like in lm() or any ather
  advanced regression model. I would be grateful for a tip how to do this.
  
   Here is an illustration of what I want:
  
   n - 100
   data - data.frame(x=rnorm(n), y=rnorm(y), z=rnorm(z))
  
   # this works
   evalq({ i - 0x; summary(y[i] + z[i]) }, data)
  
   # I want to do the above w/o explicit subscripting, e.g.
   myevalq(summary(y + z), subset=0x, data)
  
   Thanks,
   Vadim
  
  [[alternative HTML version deleted]]
  
   __
   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
   and provide commented, minimal, self-contained, reproducible code.
  
 


__
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and provide commented, minimal, self-contained, reproducible code.