Displaying 20 results from an estimated 120 matches similar to: "How do I access class slots from C?"
2009 Sep 16
2
I want to get a reference to this time series object
I'm trying to get a reference to this object in C
SWX.RET[1:6,c("SBI,"SPI","SII")]
While i am able to access and use a plain SWX.RET object, I'm getting
confused on how to create an object with the array subscripts like above.
Here is what I tried to do. It doesn't work because "[" is obviously not an
operation or function on SWX.RET. So how do I
2009 Jul 10
3
strange strsplit gsub problem 0 is this a bug or a string length limitation?
I was working with the rmetrics portfolioBacktesting function and dug into
the code to try to find why my formula with 113 items, i.e. A1 thru A113,
was being truncated and I only get 85 items, not 113.
Is it due to a string length limitation in R or is it a bug in the strsplit
or gsub functions, or in my string?
I'd very much appreciate any suggestions
============Input script:
2010 Mar 17
1
accessing info in object slots from listed objects using loops
Hey,
I have stacked a couple of garchFit objects in a list with names $fit1,
$fit2, ..., $fiti assigning objects names using a loop, i.e. after running
the loop modelStack = list($fit1, $fit2,...,$fiti).
Thus the following apply;
a = modelStack$fit2, then a is the second garchFit object of formal class
'fGarch' with 11 slots, @call, @formula... etc.
I then want to extract information in
2008 Sep 03
1
portfolio.optim and assets with weigth equals to zero...
Hello.
I don't understand a particular output of portfolio.optim (tseries).
I have 4 assets and the portfolio.optim returns an asset with weight equals
to zero.
If I do a portfolio.optim with 3 assets, without the asset with weight
equals to zero,
it returns a completely different result.
That's I would expected the same weights as the run with 4 assets.
Below the code.
Thanks in
2008 Aug 12
1
fPortfolio constraints, maxsumW
Running R version 2.6.1 under Gentoo Linux and using the fPortfolio
package, I am having trouble specifying a sector constraint. One of the
constraints to be imposed is that assets 1 and 2 together account for no
more than 13.63% of the portfolio. My attempt at coding that
constraint, "maxsumW[1:2Assets]=13.63" fails. The relevant section of
my code file and the resulting error
2012 Sep 04
0
Calculate a minimum-variance portfolio with fPortfolio
Hello everybody,
I'm running into an issue with the fPortfolio package.
1. What I want:
Calculate the minimum-variance portfolio on 20 assets with respect to the
following constraints:
- min weight per asset = 0% (i.e. no short-selling)
- max weight per asset = 10%
- min sum of asset weights = 100% (i.e. fully invested)
- max sum of asset weights = 100% (i.e. no leverage)
2. What I
2023 Mar 23
1
`dendrapply` Enhancements
Hello Aidan,
Sorry for dropping this for a while.
? Thu, 2 Mar 2023 21:03:59 +0000
"Lakshman, Aidan H" <AHL27 at pitt.edu> ?????:
> //after
> curnode = eval(lang3(R_Bracket2Symbol, parent->node, DEND_IND), env);
lang3() always constructs a new language object. If you do end up using
eval(), it may make sense to move lang3() out of the loop and reuse the
existing object
2014 Jun 25
1
Need help on calling Head from C
Hi ,
I am trying to call head function from C . My doubt is with the parameter
n,how to pass it .
PROTECT(dfm=lang3(install("data.frame"),df,ScalarLogical(FALSE)));
SET_TAG(CDDR(dfm), install("stringsAsFactors")) ;
SEXP res = PROTECT(eval(dfm,R_GlobalEnv));
PROTECT(head=lang3(install("head"),res,ScalarInteger(1)));
head = PROTECT(eval(head,R_GlobalEnv));
I tried
2010 Jan 21
0
fPortfolio prob: maxreturnPortfolio() returns Na/NaN/Inf error
Hi - First posting here.
I am using fPortfolio to try and optimize a simple portfolio consisting of 5 daily return series. I want to maximize return subject to setTargetRisk(myspec)=0.08 using only constraints="LongOnly"
I can run feasiblePortfolio() using a spec file that specifies the weights, and it works fine.
When I run maxreturnPortfolio(mydata,myspec,"LongOnly"),
2011 Jul 10
1
Code Help
Am I missing a Package? I'm not sure why is won't read the functions. Any
help is much appreciated.
> PData = Data[,3:10]
> Spec = portfolioSpec()
Error: could not find function "portfolioSpec"
> setTargetReturn(Spec) = mean(colMeans(PData))
Error in setTargetReturn(Spec) = mean(colMeans(PData)) :
object 'Spec' not found
> Constraints =
2009 Oct 29
2
Help with lang4
Hi
I seem to have run into a situation where I have more than 3 arguments to
pass to a function from C.
the following functions help me build an expression for evaluation:
lang
lang2
lang3
lang4
What should one do if there are more arguments than lang4 can handle?
Regards
Abhijit Bera
[[alternative HTML version deleted]]
2019 Nov 01
3
R C api for 'inherits' S3 and S4 objects
Dear R developers,
Motivated by discussion about checking inheritance of S3 and S4
objects (in head matrix/array topic) I would light to shed some light
on a minor gap about that matter in R C API.
Currently we are able to check inheritance for S3 class objects from C
in a robust way (no allocation, thread safe). This is unfortunately
not possible for S4 classes. I would kindly request new
2012 May 23
2
Expected behaviour of is.unsorted?
Hi,
I've read ?is.unsorted and searched. Have found a few items but nothing
close, yet. Is the following expected?
> is.unsorted(data.frame(1:2))
[1] FALSE
> is.unsorted(data.frame(2:1))
[1] FALSE
> is.unsorted(data.frame(1:2,3:4))
[1] TRUE
> is.unsorted(data.frame(2:1,4:3))
[1] TRUE
IIUC, is.unsorted is intended for atomic vectors only (description of x in
?is.unsorted). Indeed
2019 Nov 01
4
[External] R C api for 'inherits' S3 and S4 objects
Thank you Luke.
That is why I don't use Rf_inherits but INHERITS which does not
allocate, provided in the email body.
I cannot do similarly for S4 classes, thus asking for some API for that.
On Fri, Nov 1, 2019 at 5:56 PM Tierney, Luke <luke-tierney at uiowa.edu> wrote:
>
> On Fri, 1 Nov 2019, Jan Gorecki wrote:
>
> > Dear R developers,
> >
> > Motivated by
2007 Aug 16
0
call R function in c++ program
Hi all
I don't know if my message are correct in this forums.
I create a program in c++ who use statistical function. I want to execute
this function in R (in particular for use packages ade4, lattice,
bioconductor...)
Until now, my program work for simple function ("plot", "rnorm"...) but I
can't use library
My class are :
// in constructor
int argc = 1;
2013 May 08
2
call R function from C code
Hi,
I am writing C code for R, but in middle of the routine I want to call
solve(A,b) function. What is the right way to solve linear set inside C
code? Is it ok to just invoke La_solve()?
2009 Sep 15
1
How can I use R:sort function in C code?
Hi, I wrote a C extension for R. Within the C code I wanted to invoke the
R's sort function, with the argument "index.return = TRUE". I found it is a
difficult problem, how can I do that? I have implemented the decreasing
sorting by the code "PROTECT(R_fcall = lang3(install("sort"), x, desc));",
but how to define the "index.return" argument?
Thanks in
2008 Feb 27
1
Warnings generated by log2()/log10() are really large/takes a long time to display
x <- rnorm(1e6);
y <- log(x); # or logb(x) or log1p(x)
w <- warnings();
print(object.size(w));
## [1] 480
str(w);
$ NaNs produced: language log(x)
- attr(*, "dots")= list()
- attr(*, "class")= chr "warnings"
y <- log2(x); # or log10(x)
w <- warnings();
print(object.size(w));
## [1] 8000536
str(w);
## List of 1
## $ NaNs produced: language
2009 Aug 25
2
Clarifications please.
Hi
I think I have asked these questions earlier, but I been able to find
answers from the documentation (which I found poorly written in several
places). Will someone be kind enough to give me answers and enlighten me?
(as in explain with CODE?)
I want to embed R in my application and use the fPortfolio package for
carrying out risk management computations. Right now I'm reading the
Rmetrics
2009 May 26
1
passing "..." arguments to a function called by eval()
Hi everyone,
I am starting learn to call C code from within R. So far, I've been
trying toy problems to see if I can get them to work. One of the things
I'd like to do is pass an arbitrary R function to C, evaluate the value
in the C code using eval, and then return it. I also want to allow an
arbitrary number of arguments to the function using "...".
The code for my toy