similar to: Creating a new vector ( another problem)

Displaying 20 results from an estimated 10000 matches similar to: "Creating a new vector ( another problem)"

2006 Mar 10
2
creating new vector
Hi R Users, I don't know how much is difficult my problem and even it is possible to solve in R or not. Given a vector with 2000 observations. I want to creat a new vector from that vector so that new vector be the sum of every 5 observations sequently. That is , each new observation is sum of every 5 sequent observations, from the first observation of previous vector to the end. So
2006 Jan 08
2
Filters in waveslim
Dear R Users, For running wavelet functions using dwt( ), modwt( ), and mra( ), a wavelet filter algorithm is applied. For all these functions, default is "la8" and other possibility is "haar". In related documents, another possibilities like as symlet and coiflet ... are not cited. Besides "la8" and "haar", which wavelet filters can be used? Thank
2006 Nov 20
3
Creating a new vector
Dear R Users, Suppose we want to creat a new vector ( x ) from a current vector (y) of length 1000. The current vector y includes negative, zero and positive values. We want our new vector x includes the negative values in y, otherwise NA with the same length as y. For this, we have x=y[y<0] . Now x includes a subset of y with shorter length than y. With x=match(y,x) we would
2005 Jun 01
2
How to name variables in a single plot
Dear R Friends , I want to name my variables( more than 2 variables in a single plot) within a plot to distinct them from each other, but I cann't. How it is possible? I don't mean x and y axis using xlab or ylab. At the below , it follows some lines, only as an example that you could try please, if it is possible. I really thanks for your attention. Amir library(graphics) y<-
2005 May 30
2
How to access to sum of dissimilarities in CLARA
Dear All , Since dissimilarity is one of quality measures in clustering , I'm trying to access to the sum of dissimilarity as a whole measure. But after running my data using CLARA I obtain : 1128 dissimilarities, summarized : Min. 1st Qu. Median Mean 3rd Qu. Max. 0.033155 0.934630 2.257000 2.941600 4.876600 8.943700 But I can not find the sum of dissimilarity.How can i
2007 Aug 14
1
Slack variable in OR
Hi dear R users, Is it basically correct that a problem is ( linearly on nonlinearly ) modeled so that the slack variable is bounded by an upper bound ? If so, how it can be handled and coded practically ? for example: x1+ x2 =< b so ----> x1 + x2 + s=b s=b- x1 - x2 b- x1 - x2 =< upper value But algorithms can not calculate b- x1 - x2 , because
2006 Oct 30
1
reading only some columns from a table
Dear R users, Sometimes it is needed to read only some columns from a table, in particulare for high frequency data. How it is possible to read just some certain columns using read.table ( ). The reason could be keeping space in R and in particular accelerating in reading data when the number of rows are huge and some of them are not needed. Thank you very much, Amir
2017 Jul 30
4
Kalman filter for a time series
I found an example at http://www.bearcave.com/finance/random_r_hacks/kalman_smooth.html shown below. But it seems the structSSM function has been removed from KFAS library so it won't run. Does anyone know how to fix the code so that it runs? library(KFAS) library(tseries) library(timeSeries) library(zoo) library(quantmod) getDailyPrices = function( tickerSym, startDate, endDate ) {
2006 Feb 07
2
Prediction method for lowess,loess,lokerns,lpepa,ksmooth
Hi Every Body, I don't know why some regression functions have no related prediction function. For example lowess, loess, lokerns, lpridge, lpepa, and ksmooth. What could help? Is there any global or wrapper function so that can help? Regards, Amir Safari --------------------------------- [[alternative HTML version deleted]]
2006 Jun 21
3
sort matrix by sum of columns
Hi all, I would like to know how can I sort the cols of a matrix by the sum of their elements. a <- matrix(as.integer(rnorm(25,4,2)),10,5) colnames(a) = c("alfa","bravo","charlie","delta","echo") I guess I should use colSums, and then rearrange the matrix somehow according to the result. My idea is to display a "sorted" barplot:
2006 May 12
3
optimal way to compute matrix subtotals?
Hi! I have large matrices, one column per variable and I have a vector of factors / grouping symbols. Then I am computing subtotals for the groups but it takes pretty long and thus I wanted to ask if there is a better way to do it or if this is already the best way: subTotals <- function(x, groupvec) do.call("rbind",lapply(split(x,groupvec),colSums,na.rm=T)) Thanks reading my
2011 Apr 03
1
zoo:rollapply by multiple grouping factors
# Hi there, # I am trying to apply a function over a moving-window for a large number of multivariate time-series that are grouped in a nested set of factors. I have spent a few days searching for solutions with no luck, so any suggestions are much appreciated. # The data I have are for the abundance dynamics of multiple species observed in multiple fixed plots at multiple sites. (I total I
2005 Sep 25
2
getting variable length numerical gradient
Hi all. I have a numerical function f(x), with x being a vector of generic size (say k=4), and I wanna take the numerically computed gradient, using deriv or numericDeriv (or something else). My difficulties here are that in deriv and numericDeric the function is passed as an expression, and one have to pass the list of variables involved as a char vector... So, it's a pure R programming
2005 Dec 07
2
Bandwidth selection for ksmooth( )
Dear R Users, Before running ksmooth( ), a suitable bandwidth selection is needed. I use some functions for this task and receive these results for my data: width.SJ(y,nb=100,method="ste") : 40.25 bcv(y,nb=100) : 40.53 ucv(y) : 41.26 bandwidth.nrd(y) : 45.43 After implementing the function ksmooth(x,y, bandwidth= each of abovementioned bandwidths), I have some NAs
2005 Jun 29
2
comparison of packages for Unit Root test
Dear R Users, Could somebody please compare the packages of unit root test ( Uroot, Ucra, tseries and fseries ) regarding the type of test ( without constant and trend, with constant , and with constant and trend ) ? Regards, Amir Safari --------------------------------- Rekindle the Rivalries. Sign up for Fantasy Football [[alternative HTML version deleted]]
2008 Feb 04
3
counts of each column that are not NA, and/or greater than column means
Hi, Given a test matrix, test <- matrix(c(1,2,3,NA,2,3,NA,NA,2), 3,3) A) How to compute the counts of each column (excluding the NA) i.e., 3, 2, 1 B) How to compute the counts of each column (excluding the NA) that are greater than the column means ? i.e., 1, 1, 0 I could write a for loop, but hope to use better alternative. [[alternative HTML version deleted]]
2007 Nov 30
1
rollapply on zoo object
Dear R users. I have zoo object "size_june" containing market-capital values: > dim(size_june) # market-cap data of 625 firms for 20 years [1] 20 625 > class(size_june) [1] "zoo" > size_june # colnames = "size.firmcode" size.34020 size.4710 size.11050 size.10660 size.9540 size.8060 size.16160 size.8080 size.9280 1988-06-30 NA
2005 Nov 29
2
Calculating the 2th power of a vector
Hi every body , I simply want to calculate the 2th power of a vector without changing the sign of values. How it is possible in R ? Thanks a lot for any idea. Amir --------------------------------- [[alternative HTML version deleted]]
2010 Jan 17
1
Confusion in 'quantile' and getting rolling estimation of sample quantiles
Guys: 1).When I using the 'quantile' function, I get really confused. Here is what I met: > x<-zoo(rnorm(500,0,1)) > quantile(x,0.8) 400 1.060258 > c=rnorm(500,0,1) > quantile(c,0.8) 80% 0.9986075 why do the results display different? Is that because of the different type of the class? 2).And I want to use the 'rollapply' function to compute a
2008 Aug 21
1
max and min with the indexes in a zoo object (or anything else that could solve the problem)
library(zoo) library(chron) t1 <- chron("1/1/2006", "00:00:00") t2 <- chron("1/31/2006", "23:45:00") deltat <- times("00:15:00") tt <- seq(t1, t2, by = times("00:15:00")) d <- sample(33:700, 2976, replace=TRUE) sin.zoo <- zoo(d,tt) #there are ninety six reading in a day d.max <- rollapply(sin.zoo, width=96, FUN=max)