similar to: Create combinations of rows

Dear All, I am using package fPortfolio to run minimum variance portfolio optimizations in R. I already know how to set portfolioSpecs, portfolio objects and constraints. Unfortunately I am not able to set the following type of constraints. I have a timeSeries object with returns data for roughly 1.5k assets for 261 subperiods (workingdays) and want to compute the global minimum variance

dear R wizards: `optimize()` requires the user to provide the brackets. I can write a bracketing routine, given a function and a starting point, but I was wondering whether there was already a "standard" user-exposed implementation. (Presumably, this is used in nlm, too; alas, nlm is in C, not native R.) regards, /iaw

Hi, I'm an R newbie and I've been struggling with a optimization problem for the past couple of days now. Here's the problem - I have a matrix of expected payouts from different stock option strategies. Each column in my matrix represents a different stock and each row represents the return to the strategy given a certain market move. So the rows are not a time series of percentage

Dear R-helpers, www.statistik.lmu.de/~*leisch*/*Sweave*/*Sweave*-Rnews-2003-2.pdf says that R CMD build creates the pdf from a .Rnw file. But when I do R CMD build followed by R CMD check it gives me a warning that there is a vignette without a PDF. My query is : when R CMD build works it creates a pdf in the doc subdirectory of the directory returned by system.file(package = mypackage) and not

I'd like to "step" through 24 histograms by using the return or click button option, as shown in the demo(graphics) demonstration. I've searched for "interactive graphics", and "waiting for page change" in R documentation but with no result. I'm sure that this is a relatively straightforward procedure. Can anyone point me to the correct solution?   Jabez

Hello, With which package can I build a yield curve using swap data with the bootstrapping method? Thanks for the reaction, André [[alternative HTML version deleted]]

Dear R users, I want to subset a daily zoo series according to its month, find % of "NA" in each month. I am finding it difficult to subset the daily dataset into monthly for the given operation.I am planning to do this for a huge dataset. Thanks in advance. Regards Vikram [[alternative HTML version deleted]]

Hi one col in my Excel file contains many numbers. But on line 3000 and some other lines are strings like "FG 1". "RODBS" seems to omit this lines. "gdata" works, but is much slower. Is this a bug of RODBC or do I apply it wrong? Example with the same "file.xlsx" library(RODBC); excel <- odbcConnectExcel2007("file.xlsx") tab <-

Hi, I need some neat ways of determing a subset of binary strings. For example, x=c(0,0,1), y=c(0,1,1), z=c(0,1,0). So x is a subset of y and z is also a subset of y, but x is not a subset of z. I tried to search R functions and packages but no hits. Any ideas? Best, Jing -- Jing Tang, PhD Senior Researcher Finnish Institute of Molecular Medicine (FIMM) FI-00014 University of

Would someone be so kind as to provide example code where they use the suggestions argument in the rgba function In genalg? I can't get it to work. The following code works just fine: GenFit <-rbga(Lower, Upper, evalFunc = evaluate) Lower and Upper are each numeric vectors with 7 elements. Evaluate is an objective function. However, when I want to use a suggested chromosome, I get an

Dear All I have a constrained optimisation problem, I want to maximise the following function t(weights) %*% CovarianceMatrix %*% weights for the weights, subject to constraints on each element within the weights & the weights vector summing to 1. i.e. weights = (x1, x2, x3), where x1 is within some given range (a +b, a - b). I have tried to do this using the optim function in R,

Folks, I have a data frame with 4861469 rows that contains an ip address xxx.xxx.xxx.xxx as one of the columns. I want to assign a site to each row based on IP ranges. To do this I have a function to split the ip address as character into class A,B,C and D components. It works but is horribly inefficient in terms of speed. I can't quite see how one of the l/s/m/t/apply functions could be

How do I sum 15 years to my dataset? original dataset dates val 1 2001-01-12 1.2 2 2001-02-12 1.2 3 2001-03-12 1.2 result dates val 1 2016-01-12 1.2 2 2016-02-12 1.2 3 2016-03-12 1.2

On Tue, 30 Jan 2024, Richard O'Keefe writes: > Given > - UTC timestamp > - a location (latitude,longitude,elevation) > I want to know > - the sun angles > - the moon angles > - the phase of the moon. > I looked on CRAN for astronomy, but didn't notice anything that seems > to offer what I want. I could try coding these functions myself, but > "if

I would like to run a for loop with an index going from 0 to 499 but the following seems to miss out the first value: C <- 499 for (i in 0:C) The alternative is: C <- 500 for (i in 1:C) { #Then every time I use i, I replace it with i-1 } Is this a good way to do it or is tere a better way? Thank you, ThomasThis message and any attachment are intended solely for the addressee and may

Hi all, Would appreciate help with transforming this: A B C D a 2 1 4 b 3 3 5 into this: A B E a 2 1 a 2 2 a 2 3 a 2 4 b 3 3 b 3 4 b 3 5 (C<=E<=D) Best, Don -- View this message in context: http://r.789695.n4.nabble.com/Expand-dataframe-according-to-limits-defined-per-row-tp3882319p3882319.html Sent from the R help mailing list archive at Nabble.com.

See, I have built my own genetic algorithm already and tested it on this problem. I have a solution, but due to the heuristic nature of GA, I cannot guarantee that it is the optimal subset. If I was simply doing this for a company project, you are spot on with the type of algorithm I would use, but I am doing this for a scientific paper. I need to be able to find the optimal subset over my

Hi, As I can see via path.expand a filename which contains a tilde anywhere gets automatically crippled. +> path.expand("a ~ b") [1] "a /home/user b" +> path.expand("a ~ b ~") [1] "a /home/user b /home/user" I want to open a file regardless whether its name contains any character unless 0. The unix filesystem allow the creation of such files, it

Hi, As I can see via path.expand a filename which contains a tilde anywhere gets automatically crippled. +> path.expand("a ~ b") [1] "a /home/user b" +> path.expand("a ~ b ~") [1] "a /home/user b /home/user" I want to open a file regardless whether its name contains any character unless 0. The unix filesystem allow the creation of such files, it

Dear R-help, I have been trying really hard to generate the following vector given the data (x) and parameter (alpha) efficiently. Let y be the output list, the aim is to produce the the following vector(y) with at least half the time used by the loop example below. y[1] = alpha * x[1] y[2] = alpha^2 * x[1] + alpha * x[2] y[3] = alpha^3 * x[1] + alpha^2 * x[2] + alpha * x[3] ..... below are