similar to: Optimization problem: selecting independent rows to maximize the mean

Displaying 20 results from an estimated 1000 matches similar to: "Optimization problem: selecting independent rows to maximize the mean"

2011 Apr 27
6
Assignments inside lapply
Dear all I would like to ask you if an assignment can be done inside a lapply statement. For example I would like to covert a double nested for loop for (i in c(1:dimx)){ for (j in c(1:dimy)){ Powermap[i,j] <- Pr(c(i,j),c(PRX,PRY),f) } } to something like that: ij<-expand.grid(i=seq(1:dimx),j=(1:dimy)) unlist(lapply(1:nrow(ij),function(rowId) { return
2010 Mar 12
1
Length as fun.aggregate in cast function of reshape package: unexpected error
Dear Everyone, I am having problems with use of the reshape package's cast function using length as an aggregating function. Unexpectedly, I receive the error: 2 arguments passed to 'length' which requires 1 I don't understand this at all - the data I'm using is very simple, and appears almost identical to that used in the ChickWeight example in the package. The problem can
2010 Feb 08
1
R ggplot2 legend text left justify
In ggplot2 how do you justify the legend text ? In the example below the opts(legend.text = theme_text(size = 9,hjust=0)) changes the size of the text OK but it remains right justified. > mydata=data.frame(RowID=c("A","B","C"),Name=c("long long long long long name","short name ","medium medium name"),Speed=c(100,140,120)) >
2012 Aug 17
2
How can we compare corresponding values of x and y (first value of x exacly matches with the first value of y)?
df <- data.frame ( "RowId" = 4:7, "x"=c("1_1", "2_2", "3_3", "3_3"), "y"=c("1_1", "3_3", "2_2", "3_3") ) How can we compare corresponding values of x and y (first value of x exacly matches with the first value of y)? If they were not matced
2020 Sep 24
1
How to use `[` without evaluating the arguments.
Hello R-devel, I am currently attempting to implement an API similar to data.table wherein single bracket subsetting can accept an unquoted expression to be evaluated in the context of my object. A simple example from the data.table package looks like this: DT <- data.table(col1 = c('a', 'b', 'c'), col2 = c('x', 'y', 'z')) DT[col1 ==
2012 Mar 07
1
SELECT CASE in RODBC
Hi all, I have a problem with a variable created by a SELECT CASE statement. See the code below. I would like the variable "event" to be a character variabel as I want to UNION my two SELECTs - and the "event"-variable is a character variable in the first SELECT result. I have tried different ways: * used ' ' in stead of " " around the string I want as the
2006 Jan 16
8
AJAX + Table.
Hello all. I am trying ot load table rows using AJAX based on a search. The following code results in: 1. Firefox renders correctly (Multiple rows inserted into page). 2. Opera renders the entire returned string in one <td> by the looks of it (Bunched up under first header, the <> tags arne''t visible) 3. IE6 does nothing....great ;) This is driving me nuts so any help
2010 Mar 31
2
Simplifying particular piece of code
Hello, everyone I have a piece of code that looks like this: mrets <- merge(mrets, BMM.SR=apply(mrets, 1, MyFunc, ret="BMM.AV120", stdev="BMM.SD120")) mrets <- merge(mrets, GM1.SR=apply(mrets, 1, MyFunc, ret="GM1.AV120", stdev="GM1.SD120")) mrets <- merge(mrets, IYC.SR=apply(mrets, 1, MyFunc, ret="IYC.AV120",
2013 Apr 26
1
Stratified Random Sampling Proportional to Size
Hello R Experts, I kindly request your assistance on figuring out how to get a stratified random sampling proportional to 100. Below is my r code showing what I did and the error I'm getting with sampling::strata # FIRST I summarized count of records by the two variables I want to use as strata Library(RODBC) library(sqldf) library(sampling) #After establishing connection I query the data
2012 Jun 01
4
[PATCH v3] virtio_blk: unlock vblk->lock during kick
Holding the vblk->lock across kick causes poor scalability in SMP guests. If one CPU is doing virtqueue kick and another CPU touches the vblk->lock it will have to spin until virtqueue kick completes. This patch reduces system% CPU utilization in SMP guests that are running multithreaded I/O-bound workloads. The improvements are small but show as iops and SMP are increased. Khoa Huynh
2012 Jun 01
4
[PATCH v3] virtio_blk: unlock vblk->lock during kick
Holding the vblk->lock across kick causes poor scalability in SMP guests. If one CPU is doing virtqueue kick and another CPU touches the vblk->lock it will have to spin until virtqueue kick completes. This patch reduces system% CPU utilization in SMP guests that are running multithreaded I/O-bound workloads. The improvements are small but show as iops and SMP are increased. Khoa Huynh
2013 Feb 11
2
How to plot doubles series with different location using plotCI
Dear list members, I would like to create two series of plotted mean values and error bars, yet with different locations along the x-axis. Plotting of first series using plotCI with the standard arguments goes without any problem. However I do not succeed to add the second series in the same plot, which should be horizontally shifted from the first series along the x-axis. The “add=TRUE”
2002 Mar 01
3
calculating std err (SEM)?
Is there a "canned" function in R for finding the standard error of the mean? I have tried > sem <- function(x) c(mean =mean(x), + SEM = stdev(x)/sqrt(length(x))) > sem(pnet.lai) Error in sem(pnet.lai) : couldn't find function "stdev" It looks like there is no stdev function in R Thanks, Kirk Kirk R. Wythers email: kwythers at umn.edu University of
2010 Apr 21
2
Maximum Likelihood Estimation in R
Dear R-Help, I also send the following post by e-mail to you, however I try to post it here aswell. My name is Henrik and I am currently trying to solve a Maximum Likelihood optimization problem in R. Below you can find the output from R, when I use the "BFGS" method: The problem is that the parameters that I get are very unreasonable, I would expect the absolute value of each
2002 Feb 22
2
errors in integrate function?
I have been trying the integrate function in R, a function which would be very useful for a current project of mine. But I am encountering errors integrating the one function I have tried. The function to be integrated is a product of a gamma demsity and a normal density: gamma.by.normal_function(y,x,shape,scale,stdev) return( dgamma(y,shape=shape,scale=scale)*
2010 Nov 04
5
ggplot output
Dear All, I have this script: dat <- data.frame(Month = hstat$Date,C_avg = hstat$C.avg,C_stdev = hstat$C.stdev) ggplot(data = dat, aes(x = Month, y = C_avg, ymin = C_avg - C_stdev, ymax = C_avg + C_stdev)) + geom_point() + geom_line() + geom_errorbar() dat <- data.frame(Month = hstat$Date,K_avg = hstat$K.avg,K_stdev = hstat$K.stdev) ggplot(data = dat, aes(x = Month, y = K_avg,
2006 Oct 26
4
Header of dataframe
Hi I am fairly new to R and I would appreciate some help to hopefully a trivial problem. I created a function: summary.aggregate <- function(y, ...) { temp.mean <- aggregate(y, FUN=mean, ...) temp.sd <- aggregate(y, FUN=sd, ...) temp.length <- aggregate(y, FUN=length, ...) temp <- data.frame(cbind(mean=temp.mean$x,stdev=temp.sd$x,n=temp.length$x)) } this outputs e.g.:
2009 Sep 28
2
probability density function for maximum values in repeated finite samples from a normal distribution??
this is probably not really a R specific question, if so apologies for off-topic posting: I'm interested in the probability density function of the maximum values from repeated samples of size N from a normal distribution: smp <- rnorm(N, meanval, stdev) with some mean 'meanval' and standard deviation 'stdev'. I would like to know what is the frequency distribution of
2017 Oct 10
2
small files performance
2017-10-10 8:25 GMT+02:00 Karan Sandha <ksandha at redhat.com>: > Hi Gandalf, > > We have multiple tuning to do for small-files which decrease the time for > negative lookups , meta-data caching, parallel readdir. Bumping the server > and client event threads will help you out in increasing the small file > performance. > > gluster v set <vol-name> group
2008 Sep 05
2
typo in cov()? var() fails on NA in R 2.7.2 but not R 2.6.1
I recently started using R 2.7.2, and noticed a surprising change in the behavior of var() on NA data: R 2.6.1 (Patched), 2007-11-26, svn.rev 43541, x86_64-unknown-linux-gnu: > stdev(rep(NA,3), na.rm=F) [1] NA > stdev(rep(NA,3), na.rm=T) [1] NA > var(rep(NA,3), na.rm=T, use="complete.obs") [1] NA R 2.7.2 (Patched), 2008-09-02, svn.rev 46491,