similar to: hash or other quick lookup function?

Hello, which.max() only returns one index value, the one for the maximum value. If I want the two index values for the two largest values, is this a decent solution, or is there a nicer/better R'ish way? max2 <-function(v) { m=which.max(v) v[m] = -v[m] m2=which.max(v) result=c(m, m2) result } Seems to work ok. Thanks, Esmail

Hello, I have the following task I'd like to accomplish: A file contains 5 columns of data (several hundred rows), let's call them a, b, c, d and e (ie these are their column headers) I also have a set of definitions, e.g., f = a + b g = a * 3 h = c + d etc. I would like to write out a new .rda file that contains columns a b c d e f g h etc. I.e. , the original data plus new columns

Once again I need to tap into the collective knowledge here. Let's say I have the following columns and data below Y X1 X2 X3 X4 I would like to generate additional new columns and column names (ie the data would be squared - and I'd like the column names to reflect this) like: Y X1 X2 X3 X4 X1^2 X2^2 X3^2 X4^2 I believe I can compute the values correctly with the code below, but I

(sorry if this is a duplicate-problems with posting at my end) ---- Hello all, I need some help with a nice R-idiomatic and efficient solution to a small problem. Essentially, I am trying to eliminate randomly half of the entries in a vector that contains index values into some other vectors. More details: I am working with two strings/vectors of 0s and 1s. These will contain about 200

Hello, Still a newbie with R, though I have learned a lot from reading this list. I'm hoping someone can help with this question: I have two vectors, one for variables, and one for bits. I want to build a string (really a formula) based on the values in my vector of 1s and 0s in bits. If I have a one, I want to include the corresponding entry in the vars vector, otherwise ignore it. Of

Hi, I am trying to use the optimize function to optimize a function. The results I am getting don't agree with what I compute on my own and when I look at the graph of f(x) = 100 + ((x-10)**2 + (x-10)) * cos(x-10), where -10 <= x <= 10 in gnuplot. I suspect I am making a mistake in the usage of the R optimize function, perhaps someone could point out where? >

Hi, I have matrix of bits and a target vector. Is there an efficient way to search the rows of the matrix for the target? I am interested in the first row index where target is found. Example: > source("lookup.R") [,1] [,2] [,3] [,4] [,5] [1,] 1 0 1 1 0 [2,] 1 1 0 1 0 [3,] 0 0 1 0 0 [4,] 1 0 0 1 1 [5,]

Hello all, I am trying to implement a simple Genetic Algorithm using some of the functions of R (such as lm). I am a total newbie with regard to R, but not programming or GAs. I thought I would have to do this in R but now it seems there are ways to call R functions from Java after all. (C++ would work for me too, having a compiled language should speed up the program.) Are there recommended

Hello all, Using Ubuntu 9.04 and R 2.8.1. For a project I need to use the Zelig package, which in turn wants to use the lme4 package. When trying to use Zelig and it tries to its required packages I get the following error message. Error in dyn.load(file, DLLpath = DLLpath, ...) : function 'cholmod_start' not provided by package 'Matrix' Error in loadModelDeps(model) :

Colleagues, I have encountered behavior of random number generation that eludes me. I generate a random integer in a particular range using the following code: sample(1000:9999, size=1) This code exists within a script that starts with the command: remove(list=ls()) Each time that I run the script, it yields the same random number: 6420. I thought that the problem might result from

I have a string of binary values, and I would like to flip certain bits in a set of positions. Let's say the vector p contains position [1, 3, 5, 7] vector b contains bits [1, 0, 1, 0, 1, 0, 1, 0, 1, 0] result r should be [0, 1, 0, 0, 0, 0, 0, 0, 1, 0] in pseudo code this would be something like --- r = c() for (i in 1:10) if (i in p) r = c(r, flip[i]) r ----

Perhaps most of you have already seen this? http://google-styleguide.googlecode.com/svn/trunk/google-r-style.html Comments/Critiques? Thanks, Esmail ps: Reminds me of PEP 8 for Python http://www.python.org/dev/peps/pep-0008/ Maybe not that surprising since Python is also one of the main languages used by Google.

# HG changeset patch # User Olaf Hering <olaf@aepfle.de> # Date 1338572607 -7200 # Node ID 3da83ff08d6b6431c104a431d6617ccb5977643b # Parent fde8ad0252ee6ddb8d71dda869db3b20b3d9ca62 xl.cfg: document the cpuid= option Signed-off-by: Olaf Hering <olaf@aepfle.de> diff -r fde8ad0252ee -r 3da83ff08d6b docs/man/xl.cfg.pod.5 --- a/docs/man/xl.cfg.pod.5 +++ b/docs/man/xl.cfg.pod.5 @@ -969,9

I've been trough the R documentation for about half an hour and it's not clear to me how to do this: I need to format to character a series of integers from 1 to 1000, and I like them to look like "0001" "0002", "0059", "0123" and so on. Padded with zeroes to have four digits. Cheers! Mario. r-help-request at r-project.org wrote: > Send

Dear sir, I am using R in windows. I want to extend R Memory size. I use the following command, but unfortunately it doesn't work. -- vsize=15M --nsize=1000K Your help is appreciated. Thanks, Esmail Amiri. __________________________________________________ Do You Yahoo!? Get email at your own domain with Yahoo! Mail. http://personal.mail.yahoo.com/

I'm trying to compare two matrices made up of bits. doing a simple comparison of matA == matB yields this sort of output. [,1] [,2] [,3] [,4] [,5] [,6] [1,] FALSE TRUE FALSE TRUE TRUE FALSE [2,] TRUE TRUE TRUE TRUE TRUE TRUE [3,] FALSE TRUE FALSE FALSE FALSE TRUE [4,] FALSE TRUE TRUE FALSE FALSE FALSE [5,] TRUE TRUE TRUE TRUE FALSE FALSE [6,] TRUE TRUE

Hello all, I am stuck with R v2.8.0 under Linux for the time being and I am running into a small problem that doesn't exist under 2.9.x and 2.10.x with sprintf. If I have the following code segment to help me determine the column number for a specific column header/label: nn = names(Dataset) s = "Group" c = which(nn==s) cat(sprintf('found %s in col %d\n', s, c))

Hello, would someone please help explain the following inconsistency in the if/else statement to me? The format of the if/else #3 below is ok, but if/else #1 is not? (I get an "unexpected else" type error.) In order for it to work I have to use if/else #2 Thanks .. maybe there is some reason for this, but this looks very inconsistent to me. R version 2.10.1 (2009-12-14) Ubuntu 9.04

Hello all, I would like to maximize or minimize a given math function over a specific set of values. I was checking out Wolfram Alpha (http://www70.wolframalpha.com/) and it can do simple optimization problems in math, such as maximize 15*x - x**2 over 0 to 15 (http://www70.wolframalpha.com/input/?i=maximize+15*x+-+x**2+over+0+to+15) which finds the maximum value and input for x in

Hello all, I have two matrices, pop and pop2, each the same number of rows and columns that I want to compare for equality. I am concerned about efficiency in this operation. I've tried a few things without success so far. Doing something simple like: if (pop==pop2) { cat('equal') } else { cat('NOT equal') } results in the warning: 1: In if (pop == pop2) { : the