similar to: Matrix/Vector manipulation

Displaying 20 results from an estimated 400 matches similar to: "Matrix/Vector manipulation"

2012 Jul 18
4
The best solver for non-smooth functions?
# Hi all, # consider the following code (please, run it: # it's fully working and requires just few minutes # to finish): require(CreditMetrics) require(clusterGeneration) install.packages("Rdonlp2", repos= c("http://R-Forge.R-project.org", getOption("repos"))) install.packages("Rsolnp2", repos= c("http://R-Forge.R-project.org",
2018 Apr 18
2
Event-triggered change in value with a time-delay
Hello, I am solving a set of ODEs using deSolve and have run into a problem I would appreciate some advice on. One of the parameters (m) in the ODEs changes between two states when one of the variables (D) crosses a threshold (D_T) for the first time in either direction. Additionally, when the variable crosses the threshold (either by increasing or decreasing), there is a time delay (delay)
2018 Apr 18
0
Event-triggered change in value with a time-delay
> On Apr 18, 2018, at 1:04 AM, Hannah Meredith <hrmeredith12 at gmail.com> wrote: > > Hello, > > I am solving a set of ODEs using deSolve and have run into a problem I > would appreciate some advice on. One of the parameters (m) in the ODEs > changes between two states when one of the variables (D) crosses a > threshold (D_T) for the first time in either direction.
2017 Aug 26
2
Register Allocation and Scheduling Issues
Hello, I have defined 8 registers in registerinfo.td file in the following order: R_0, R_1, R_2, R_3, R_4, R_5, R_6, R_7 But the generated assembly code only uses 2 registers. How to enable it to use all 8? Also can i control the ordering like after R_0 can i use R_5 without changes in registerinfo.td? What changes are required here? either in scheduling or register allocation phases?
2004 Nov 14
1
Combining expressions and objects within labels
Hello all, I am an R novice and I have a simple question and hope somebody can help me out. I need to place several labels in a plot, this labels are some kind of text and also some objects (which come from some more complicated R calculations). In one of this labels I'd like to place a superscript, however I cannot find a way to place both the expression and the object in the same
2018 Mar 25
0
R-devel Digest, Vol 181, Issue 22
Thanks. I am fully aware of what aggregate() returnes, and I can post-process this into the form I want ? if the names are available. But for foo, the returned object is both different in structure and loses the name altogether: foo <- function(x) { c(mean = base::mean(x)) } str(aggregate(iris$Sepal.Length, by = list(iris$Species), FUN = foo)) ## 'data.frame': 3 obs. of 2 variables:
2002 Feb 06
4
Weighted median
Is there a weighted median function out there similar to weighted.mean() but for medians? If not, I'll try implement or port it myself. The need for a weighted median came from the following optimization problem: x* = arg_x min (a|x| + sum_{k=1}^n |x - b_k|) where a : is a *positive* real scalar x : is a real scalar n : is an integer b_k: are negative and positive scalars
2007 Jul 26
1
significance test for difference of two correlations
Dear R users, how can I test, whether two correlations differ significantly. (I want to prove, that variables are correlated differently, depending on the group a person is in.) Greetings from Freiburg im Breisgau (Germany), Timo Stolz
2007 Nov 19
2
All nonnegative integer solution
Dear all, Is there any method in R to find all possible nonnegative integer solutions to the linear equation with unit coefficients as follow: X1+X2+...+Xk=N Thank you, Amin Zollanvari
2017 Jun 25
0
AVX Scheduling and Parallelism
Hi, Zvi, I agree. In the context of targeting the KNL, however, I'm a bit concerned about the addressing, and specifically, the size of the resulting encoding: > vmovdqu32 zmm0, zmmword ptr [rax + c+401280] ;load b[401280] in > zmm0 > > vpaddd zmm1, zmm1, zmmword ptr [rax + b+401344] > ; zmm1<-zmm1+b[401344] The KNL can only
2017 Jun 25
2
AVX Scheduling and Parallelism
Hi Ahmed, >From what can be seen in the code snippet you provided, the reuse of XMM0 and XMM1 across loop-unroll instances does not inhibit instruction-level parallelism. Modern X86 processors use register renaming that can eliminate the dependencies in the instruction stream. In the example you provided, the processor should be able to identify the 2-vloads + vadd + vstore sequences as
2011 Jul 03
3
Hint improve my code
Hi I have developed the code below. I am worried that the parameters I want to be estimated are "not being found" when I ran my code. Is there a way I can code them so that R recognize that they should be estimated. This is the error I am getting. > out1=optim(llik,par=start.par) Error in pnorm(au_j, mean = b_j * R_m, sd = sigma_j) : object 'au_j' not found #Yet
2011 Jul 01
2
Help fix last line of my optimization code
Hi I need help figure out how to fix my code. When I call into R >optimize(llik,init.params=F) I get this error message ####Error in optimize(llik, init.params = F) : element 1 is empty; the part of the args list of 'min' being evaluated was: (interval)#### My data and my code looks like below. R_j R_m 0.002 0.026567296 0.01 0.003194435 . . . . . . . . 0.0006
2011 Jul 04
3
loop in optim
Hi May you help me correct my loop function. I want optim to estimates al_j; au_j; sigma_j; b_j by looking at 0 to 20, 21 to 40, 41 to 60 data points. The final result should have 4 columns of each of the estimates AND 4 rows of each of 0 to 20, 21 to 40, 41 to 60. ###MY code is n=20 runs=4 out=matrix(0,nrow=runs) llik = function(x) { al_j=x[1]; au_j=x[2]; sigma_j=x[3]; b_j=x[4]
2011 Jul 23
1
Extend my code to run several data at once.
Hi I have a code that calculate maximisation using optimx and it is working just fine. I want to extend the code to run several colomns of R_j where j runs from 1 to 200. If I am to run the code in its current state, it means I will have to run it 200 times manually. May you help me adjust it to accomodate several rows of R_j and print the 200 results. ***Please do not get intimidated by the
2011 Jul 06
1
Group Data indexed by n Variables
Hello, the more general thing I'd like to learn here is how to compute Function of Data on the basis of grouping determiend by n variables. In terms of the reason why I am interested in this, I need to compute the average of my data based on the value of the month and day across years. I have come up withy the code below which, as far as I can see, does what I need but getting either a more
2006 Apr 25
5
Heteroskedasticity in Tobit models
Hello, I've had no luck finding an R package that has the ability to estimate a Tobit model allowing for heteroskedasticity (multiplicative, for example). Am I missing something in survReg? Is there another package that I'm unaware of? Is there an add-on package that will test for heteroskedasticity? Thanks for your help. Cheers, Alan Spearot -- Alan Spearot Department of Economics
2008 Jan 25
1
Poisson Maximum Likelihood Estimation
Hi I am trying to carry out some maximum likelihood estimation and I'm not making much headway, and I'm hoping that someone will be able to point me in the right direction. I am modelling mortality statistics. One way to do this is to model the mortality rate (or, more accurately, log of the mortality rate, log_m) as (say) a constant plus a proportion of age, plus time, so: r_1 <-
2015 Jan 03
4
Potential cross-platform package building issue
I am using 32-bit R 3.1.2 on Windows 7. I recently conducted an `R CMD check --as-cran` on a recently-developed package and received only the 'New submission' note. Research on StackOverflow and on R-devel suggested this could be ignored. I also used devtools::build_win() and received no notes or warnings, other than the one mentioned previously. Lastly, I conducted an `R CMD check` with
2017 May 10
4
strange system outage
I have a CentOS 7 system that I run a home grown python daemon on. I run this same daemon on many other systems without any incident. On this one system the daemon seems to die or be killed every day around 3:30am. There is nothing it its log or any system logs that tell me why it dies. However in /var/log/messages every day I see something like this: May 10 03:35:58 localhost pure-ftpd: (tool at