[R] Call R program from C++ code

2007-07-29 Thread Feng Qiu
Hi All:

   I'm developing an application program using C++. From my C++
code, I would call some R program I have written. I' wondering if R provide
some compiler that can compile R program into executable program. I searched
R-help, there are a lot of posts talking about writing C++ code in R
program, but few about calling R from C++. 

   I might be wrong that R doesn't have complier. What I'm
trying to do is to call R program from C++ code. Any help is highly
appreciated!

 

Best regards,

 

Feng

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Re: [R] Call R program from C++ code

2007-07-29 Thread Feng Qiu
Hi Dirk:
Thanks a lot. 
 That does not exist to the best of my knowledge.
That's sad :(

using the system() call -- but it is also the most tedious way as you
When using System() to call R program, do I need to call some R script
program or my R function directly? 

 A more advanced method would to use Rserve to run a 'headless' R 
Here you mean Com? I don't know much about this com frame, so 

 In any event, you may also want to consider the RcppTemplate package
I'll read this package, hope I can find a simple way that works in my case.

Thanks again!

Best,

Feng

-Original Message-
From: Dirk Eddelbuettel [mailto:[EMAIL PROTECTED] On Behalf Of Dirk
Eddelbuettel
Sent: 2007年7月29日 18:17
To: Feng Qiu
Cc: r-help@stat.math.ethz.ch
Subject: Re: [R] Call R program from C++ code

On Sun, Jul 29, 2007 at 04:35:51PM -0400, Feng Qiu wrote:
I'm developing an application program using C++. From my
C++
 code, I would call some R program I have written. I' wondering if R
provide
 some compiler that can compile R program into executable program. I
searched

That does not exist to the best of my knowledge.

I might be wrong that R doesn't have complier. What I'm
 trying to do is to call R program from C++ code. Any help is highly
 appreciated!

As you probably know, C++ can 'call' other object code that is linked
to it.  As for 'calling R', the easiest way is to call an R script
using the system() call -- but it is also the most tedious way as you
to write the inout data to file, and then read the result data back
in.  But it is a start, and it may be easiest to debug.

A more advanced method would to use Rserve to run a 'headless' R
service to which your C++ program can connect over the network. But
there you need to be already somewhat familiar with the underlying
C/C++ representation of R object. Rserve has simple examples.

Next, you can actually embed R inside your C++ application, but that
is more advanced.

In any event, you may also want to consider the RcppTemplate package
which has a host of examples about how to get R and C++ to work better
together (without forcing you to use C).

The 'Extending R' manual from your R installation is a good starting
point for most of this.

Hope this helps, Dirk

-- 
Three out of two people have difficulties with fractions.


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[R] how to preserve trained model in LDA?

2007-05-30 Thread Feng Qiu
Hi all:

   I'm developing an application in which I use standard data to
train the model in LDA and use the trained model to predict on test data. I
can't train the model every time when I do prediction. So I need to save the
trained model onto disk after the first training. Does anybody have idea
about this? You help is highly appreciated. 

 

Best Regards

 

Feng


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[R] anyone konw Polyclass package in R?

2007-05-10 Thread Feng Qiu
Hi everyone:

  Polyclass is a polytomous logistic regression model using
linear splines and their tensor products. It provides estimates for
conditional class probabilities which can then be used to predict class
labels. I know there is Polyclass package in S-plus. So I'm wondering if
there is a corresponding package in R? I have been searching for it for
quite a while, but still haven't found it. You help is appreciated very
much!

 

Best regards

 

Feng

 


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Re: [R] how to get the index of entry with max value in an array?

2007-01-18 Thread Feng Qiu
Thank you guys! I got it.

Best,

Feng

- Original Message - 
From: Benilton Carvalho [EMAIL PROTECTED]
To: Feng Qiu [EMAIL PROTECTED]
Cc: r-help@stat.math.ethz.ch
Sent: Thursday, January 18, 2007 12:20 AM
Subject: Re: [R] how to get the index of entry with max value in an array?


 which.max()
 b
 
 On Jan 17, 2007, at 11:20 PM, Feng Qiu wrote:
 
 Hi all:
  A short question:
  For example,  a=[3,4,6,2,3], obviously the 3rd entry of  
 the array has the maxium value, what I want is index of the maxium  
 value: 3. is there a neat expression to get this index?

 Thank you!

 Best,

 Feng

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[R] how to get the index of entry with max value in an array?

2007-01-17 Thread Feng Qiu
Hi all:
 A short question:
 For example,  a=[3,4,6,2,3], obviously the 3rd entry of the array has 
the maxium value, what I want is index of the maxium value: 3. is there a neat 
expression to get this index? 

Thank you!

Best,

Feng


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[R] How to use RBF nueral network to predict

2007-01-11 Thread Feng Qiu
Hi all:
  I'm trying to use RBF neural network for predicting. The package 
I'm using now is neural. The type of network that I have to use is RBF. 
But I didn't find predict function in this package. Does anyone have such an 
experience?  Any advice is appreciated!
   Thank you!

Best,

Feng

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[R] logistic regression packages

2007-01-10 Thread Feng Qiu
Hi All:
   I'm testing a set of data classification algorithms in this paper 
(www.stat.wisc.edu/~loh/treeprogs/quest1.7/mach1317.pdf )
I couldn't find such algorithms in R packages:
   1. LOG: polytomous logistic regression (there was one in MASS 
library: multinom. But after I update MASS library, multinom was lost.)
   2. POL: POLYCLASS algorithm. There is a S-Plus package(polyclass 
library) for this algorithm, so there should be a corresponding package in 
R, but I haven't found it so far.
   Any advice is appreciated.

Best,

Feng

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Re: [R] logistic regression packages

2007-01-10 Thread Feng Qiu
Hi David:
 Thanks for you information. 2 further questions:
  1. I found out that multinom is not doing politomous logistic 
regression, do you know which function does this?
  2. the polyclass in polspline does polychotomous regression, 
while I'm looking for polytomous regression. Do you think these two are 
similar int erms of prediction?

Best,

Feng


- Original Message - 
From: David Barron [EMAIL PROTECTED]
To: r-help r-help@stat.math.ethz.ch
Sent: Wednesday, January 10, 2007 12:14 PM
Subject: Re: [R] logistic regression packages


 1. multinom is is the nnet package

 2. There is a polyclass function in package polspline

 On 10/01/07, Feng Qiu [EMAIL PROTECTED] wrote:
 Hi All:
I'm testing a set of data classification algorithms in this 
 paper
 (www.stat.wisc.edu/~loh/treeprogs/quest1.7/mach1317.pdf )
 I couldn't find such algorithms in R packages:
1. LOG: polytomous logistic regression (there was one in MASS
 library: multinom. But after I update MASS library, multinom was lost.)
2. POL: POLYCLASS algorithm. There is a S-Plus 
 package(polyclass
 library) for this algorithm, so there should be a corresponding package 
 in
 R, but I haven't found it so far.
Any advice is appreciated.

 Best,

 Feng

 __
 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
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 --
 =
 David Barron
 Said Business School
 University of Oxford
 Park End Street
 Oxford OX1 1HP


 -- 
 =
 David Barron
 Said Business School
 University of Oxford
 Park End Street
 Oxford OX1 1HP

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[R] Is there a function for this?

2007-01-03 Thread Feng Qiu
Hi everybody, I'm trying to do a statistic on the error rate of a prediction 
algorithm.

suppose this is the real category
[good, good, bad, bad, good, good, bad, bad]
this is the predicted category
[good, bad, bad, bad, good, good, good, bad]

I'm trying to do a statistic on the error rate for each group(good,bad): 
what percentage of instances are predicted incorrectly for each group ?
Of course I can write a loop to do that, but is there a easy way to do that?

Thank you!

Best,

Feng

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Re: [R] Any container in R?

2007-01-02 Thread Feng Qiu
Hi Thomas:
   Thanks for your explanation.
   You are right that in C++, we try to use the same piece of codes 
on different type of objects. While in R, most operations are done in a 
vector way automatically, which reduced the need for containers.

Best,
Feng
- Original Message - 
From: Thomas Lumley [EMAIL PROTECTED]
To: Feng Qiu [EMAIL PROTECTED]
Cc: Duncan Murdoch [EMAIL PROTECTED]; r-help@stat.math.ethz.ch
Sent: Monday, January 01, 2007 3:21 PM
Subject: Re: [R] Any container in R?


 On Mon, 1 Jan 2007, Feng Qiu wrote:

 Hi Duncan:
 Thank you very much! I checked out unique(), it does exactly what 
 I
 want. But I'm still curious about if R provides STL(standard template
 library).

 No.

 Some things the STL does aren't needed in R, others are implemented 
 differently, and others aren't implemented.

 One particularly important example is iterators, which will often either 
 happen invisibly due to vectorized operations or will be done with the 
 *apply family of functions.

 Your example could have been done either way. Using duplicated() is the 
 vectorized approach; the apply approach would use tapply().

 C++ is not terribly similar to R. A lot of the effort in STL is expended 
 on allowing a piece of code to be used on different types (where 
 appropriate). In R you have to expend effort on stopping a piece of code 
 being used on different types (where inappropriate).


  -thomas

 Thomas Lumley Assoc. Professor, Biostatistics
 [EMAIL PROTECTED] University of Washington, Seattle





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[R] Any container in R?

2007-01-01 Thread Feng Qiu
R has list and array to contain elements. But does R have more powerful 
container, such as map as in C++ STL?  or is there such a package?

Thanks and Happy 2007!

Best,

Feng

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Re: [R] Any container in R?

2007-01-01 Thread Feng Qiu
Hi Duncan:
 Thanks for your hints.
 I'm trying to collect distinct elements in one column in a matrix. 
If there is a map, I can easily build up such a collection. While if using 
list, I have to check by myself if this element already exists in the 
collection every time I examine a new entry in the column.

Best,

Feng

- Original Message - 
From: Duncan Murdoch [EMAIL PROTECTED]
To: Feng Qiu [EMAIL PROTECTED]
Cc: r-help@stat.math.ethz.ch
Sent: Monday, January 01, 2007 10:37 AM
Subject: Re: [R] Any container in R?


 On 1/1/2007 10:17 AM, Feng Qiu wrote:
 R has list and array to contain elements. But does R have more powerful 
 container, such as map as in C++ STL?  or is there such a package?

 In what way are maps more powerful than lists?  You can use names to index 
 lists.

 The other container in R is the environment; they have fairly strange 
 semantics, though.

 Duncan Murdoch



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Re: [R] Any container in R?

2007-01-01 Thread Feng Qiu
Hi Duncan:
 Thank you very much! I checked out unique(), it does exactly what I 
want. But I'm still curious about if R provides STL(standard template 
library).

Best,

Feng


- Original Message - 
From: Duncan Murdoch [EMAIL PROTECTED]
To: Feng Qiu [EMAIL PROTECTED]
Cc: r-help@stat.math.ethz.ch
Sent: Monday, January 01, 2007 12:36 PM
Subject: Re: [R] Any container in R?


 On 1/1/2007 11:22 AM, Feng Qiu wrote:
 Hi Duncan:
  Thanks for your hints.
  I'm trying to collect distinct elements in one column in a 
 matrix. If there is a map, I can easily build up such a collection. While 
 if using list, I have to check by myself if this element already exists 
 in the collection every time I examine a new entry in the column.

 You might want to use the unique() function, or duplicated(), rather than 
 doing this yourself.

 Duncan Murdoch


 Best,

 Feng

 - Original Message - 
 From: Duncan Murdoch [EMAIL PROTECTED]
 To: Feng Qiu [EMAIL PROTECTED]
 Cc: r-help@stat.math.ethz.ch
 Sent: Monday, January 01, 2007 10:37 AM
 Subject: Re: [R] Any container in R?


 On 1/1/2007 10:17 AM, Feng Qiu wrote:
 R has list and array to contain elements. But does R have more powerful 
 container, such as map as in C++ STL?  or is there such a package?
 In what way are maps more powerful than lists?  You can use names to 
 index lists.

 The other container in R is the environment; they have fairly strange 
 semantics, though.

 Duncan Murdoch






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Re: [R] Problems with R

2007-01-01 Thread Feng Qiu
You got to supply the absolute path of your files and the seperating symbol 
in your csv file.
Please read the help file by typing help(read.csv),  you will have no 
problem.


- Original Message - 
From: Obinna Duru [EMAIL PROTECTED]
To: r-help@stat.math.ethz.ch
Sent: Monday, January 01, 2007 4:09 AM
Subject: [R] Problems with R



 Hello,

 Please I have problems with R. I downloaded R from UC Berkeley CRAN
 mirror, but each time I try to read a data file using the command
 'moi.data - read.csv(choose.files())' or 'my.data - choose.files()
 #' , the program becomes unstable and exits itself.

 However, I just noticed from my Windows Task manager that the
 R-program process tree is still active and using up about 30% of the
 processor activity.

 Is this a problem with my download? I have tried reinstalling from UC
 Los Angeles, but still have the same issues.

 Any help will be appreciated. I need to use the acepack package in R.

 Thank you


 Best Regards

 Obinna Duru

 Energy Resources Engineering Department,
 Green Earth Sciences Building,
 367 Panama Street,
 Stanford, CA 94305-2220
 cell:   (650) 814 6079
 fax:(659) 725 2099
 email:  [EMAIL PROTECTED]





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Re: [R] How to write string dynamicly?

2006-12-28 Thread Feng Qiu
Hi Gabor:
  Thank you!  But it didn't work. Since lda() takes the variable 
name as the input parameter. So what I was trying to do is make the name 
dynamically. I used sprintf() to generate a variable name, such as V16. 
But it seems that the function doesn't recognize the generated name. For 
example, lda(V16,data=mydata) works, But,
lda(sprintf(V%d,k),data=mydata) does not work, where k=16.  So I guess the 
name generated by sprintf is not the parameter wanted. But I have no idea 
about it.

Best,

Feng


- Original Message - 
From: Gabor Grothendieck [EMAIL PROTECTED]
To: Feng Qiu [EMAIL PROTECTED]
Cc: r-help@stat.math.ethz.ch
Sent: Wednesday, December 27, 2006 1:56 PM
Subject: Re: [R] How to write string dynamicly?


 Try:

 lda(iris[-5], iris[,5])

 On 12/26/06, Feng Qiu [EMAIL PROTECTED] wrote:
 Hi everyone:
 I'm trying to compose a string dynamicly for the parameter input 
 of
 some function. For example:
 In package MASS, function lda() require to input the name of predictor
 variable. Let's say the 16th column is the predictor variable. Then we 
 call
 the function like this: lda(V16~., data=mydata). I don't want to 
 hard-code
 the call, instead, I would like to use a dynamic expression for this
 parameter so that I can use my program on different set of data.
I guess there,- are some function that can do this, but I didn't 
 find
 it in Introduction to R so far, could someone please tell me this kind 
 of
 function? Thank you!

 Best,

 Feng

 __
 R-help@stat.math.ethz.ch mailing list
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[R] How to write string dynamicly?

2006-12-27 Thread Feng Qiu
Hi everyone:
 I'm trying to compose a string dynamicly for the parameter input of 
some function. For example:
In package MASS, function lda() require to input the name of predictor 
variable. Let's say the 16th column is the predictor variable. Then we call 
the function like this: lda(V16~., data=mydata). I don't want to hard-code 
the call, instead, I would like to use a dynamic expression for this 
parameter so that I can use my program on different set of data.
I guess there are some function that can do this, but I didn't find 
it in Introduction to R so far, could someone please tell me this kind of 
function? Thank you!

Best,

Feng

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[R] How to debug R program?

2006-12-27 Thread Feng Qiu


 Hi everyone:
   I wrote a R program which has loops. When I run the program, it 
 crashed. I would like to identify in which loop the pragram crashed, how 
 can I debug ?  I'm new to R, could somebody please give me a general idea 
 about debugging in R.(I'm a C/C++ programmer and have general knowledge 
 about program debugging.)
  Thank you!

 Best,

 Feng


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[R] packages about discriminant analysis

2006-11-29 Thread Feng Qiu
Hi guys:
   I'm testing some statistic discriminant analysis methods in R. 
But I couldn't find the package for these methods:
   1. Discriminant analysis implemented with nearest neighbor 
method,
   2. logistic discriminant analysis
   3. POLYCLASS algorithm( there is such a function in S-Plus, 
namely poly.fit from polyclass library. Is there a corresponding library in 
R? )
   Any kind of help is highly appreciated!

Best,

Feng

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[R] Help concerning Lasso::l1ce

2005-02-11 Thread Feng Qiu
Hi, 
First, when I try the example Prostate with bound 0.44
(as in the manual), I got a different result:

 l1c.P - l1ce(lpsa ~ ., Prostate, bound=0.44)
 l1c.P
…
Coefficients:
(Intercept)  lcavol lweight age   
lbph svi
  1.0435803   0.4740831   0.1953156   0.000  
0.000   0.3758199
lcp gleason   pgg45
  0.000   0.000   0.000
 The relative L1 bound was  : 0.44
The absolute L1 bound was  : 0.8113534
The Lagrangian for the bound is:  17.89198

And the sum of the absolute values of the coefficients
are larger than the bound!! Why?

Second, the manual says that if I set sweep.out to
NULL, the constant term (which is the intercept,
right?)
will be included in the bound, but when I do so, I get
an error “Matrix build from transformed variables has
a constant column”. Why?
And how can I constrain the constant term?

Finally, could anyone explain to me the difference
between relative bound and absolute bound? Which is
the actually bound adopted?

I’m new to R and the lasso2 package, please help
me out, thank you very much.

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