similar to: do calculations as defined by a string / expand mathematical statements in R

Hi, I search a way to replace multiple occurrences of a string with different strings depending on the place where it occurs. I tried the following; x <- c("xx y e d xx e t f xx e f xx") x <- gsub("xx", c("x1", "x2", "x3", "x4"), x) what I want to get is; x = x1 y y e d x2 e t f x3 e f x4 but what I get is; x = x1 y y e

Dear R-Users, I have a problem with an algorithm that iteratively goes over a data.frame and exclude n-columns each step based on a statistical criterion. So that the 'column-space' gets smaller and smaller with each iteration (like when you do stepwise regression). The problem is that in every round I use a new subset of my data.frame. However, as soon as I "generate" this

Hi, I have multiple three dimensional arrays. Like this: x1 <- array(rnorm(1000, 1, 2), dim=c(10, 10, 10)) x2 <- array(rnorm(1000, 1, 2), dim=c(10, 10, 10)) x3 <- array(rnorm(1000, 1, 2), dim=c(10, 10, 10)) Now I would like to compute the mean for each corresponding cell. As a result I want to get one 3D array (10 x 10 x 10) in which at position x, y, z is the mean of the

Hi R users I have serveral binary variables (e.g., X1, X2, X3, X4, X5, X,6, and X7) and one continuous variable (e.g., Y1). I combined these variables using data.frame() mydata <- data.frame(X1,X2,X3,X4,X5,X6,X7,Y1) after that, I sorted this data.frame rank.by.Y1<-order(mydata[,8]) sorted.mydata<-mydata[rank.by.Y1,] after that, I replaced Y1's values with values ranging from 1

Hi, May be this helps (Assuming that there are only '0's and '1's in the dataset) dat1<-read.table(text=" ??????? ID X0 X1 X2 X3 X4 X5 X6 X7 X8 X9 X10 X11 X12 X13 X14 X15 1?? 5184??? 0??? 0??? 0??? 0??? 0?? 0?? 0??? 0??? 0??? 1???? 0????? 0????? 0????? 0????? 0????? 0 2?? 6884??? 0??? 0??? 1??? 0??? 0?? 1?? 0??? 0??? 0??? 0???? 0????? 0????? 0????? 0????? 0????? 0 3?

Hi, I have a data frame with 6563 observations. I can run a regression with loess using four explanatory variables. If I add a fifth, R crashes. There are no missings in the data, and if I run a regression with any four of the five explanatory variables, it works. Its only when I go from four to five that it crashes. This leads me to believe that it is not an obvious problem with the data,

Hi, I found that the R package "KernSmooth" can deal with only 1D and 2D data. But now I have a collection of 4-dimensional data (x1,x2,x3,x4) and would like to estimate the "mode" of the underlying density. What can I do about it ? Thanks a lot. -- Ying-Chao Hung Assistant Professor Graduate Institute of Statistics National Central University Chung-Li, Taiwan TEL:

Hi R-helpers, I have a character string, for example: "lm(y ~ X2 + X3 + X4)" from which I would like to strip off the leading and trailing quotation marks resulting in this: lm(y ~ X2 + X3 + X4) I have tried using gsub() but I can't figure out how to specify the quotation mark using a regular expression. Alternatively, I would like a function that lets me delete the leading

Tried to post this last night, but it doesn't seem to have appeared. Using R 2.0.1 on Windows XP + SP2. I am traveling, away from my usual references. I'm trying to make a 4-dimensional plot: a levelplot with overlaid contours, with different response variables represented by (1) colors on the levelplot and (2) the contour lines. First try was filled.contour + contour but the key

Dear All, I'm wondering if there is a R function could give me all the combinations of the grouping/cluster result, given the number of the groups. e.g. 3 objects: x1 x2 x3, number of groups is 2 so the result will be group1:x1,x2; group2: x3 group1: x1;group2: x2,x3 group1: x1,x3;group2: x2 many thanks yan

After getting one list done, I am now struggling to form a data frame in C. I tried to do a list of lists which gives me : $<NA> $<NA>[[1]] [1] "BID" $<NA>[[2]] [1] 0.6718 $<NA>[[3]] [1] 3e+06 $<NA> $<NA>[[1]] [1] "BID" $<NA>[[2]] [1] 0.6717 $<NA>[[3]] [1] 5e+06 $<NA> $<NA>[[1]] [1] "BID"

I defined a data.frame by a two-dimensional array. > aa = data.frame(rbind( 11:20, 1:10)) > aa X1 X2 X3 X4 X5 X6 X7 X8 X9 X10 1 11 12 13 14 15 16 17 18 19 20 2 1 2 3 4 5 6 7 8 9 10 Now I want to use the data in the second line of aa which from 1 to 10 to output.But I find that when I use the aa[[1]][1:10] and it seems be mistake. aa[[1]][1:10] [1] 11 1 NA NA NA

Hi, I am still struggling with three dimensional arrays. Now I would like to convert a three dimensional array into a data-frame with the coordinate-columns: x, y, z and a value-column. And I definitely don't want to loop over every element, since this would be very resource intensive for the actual data-set. Are there any specific functions that are helpful for this task?

Hello, I try to do a very simple nonlinear regression. The function is y = (b0 + b1*x1 + b2*x2 + b3*x3) * x4^b4 I think I do everything well, but as I set the starting value of b4 to 0 (it is the theoretically sane starting value), it converges very quickly, and to the wrong solution. Wrong in a sense, that 1) we do not expect this and 2) we do not get this on E-Views, Stata and SAS. I do not

hello I make a subroutine that give-me a (mathematical) function in string format. I would like transform this string into function ( R function ). thanks for any tips. cleber #e.g. fun_String = "-100*x1 + 0*x2 + 100*x3" fun <- function(x1,x2,x3){ return( ############ evaluation( fun_String ) ############ ) True String mathematical function :-( :-( > nomes [1]

Hi R, par(mfrow=c(2,2)) x1=(1:5)^1; x2=(1:5)^2; x3=(1:5)^3; x4=(1:5)^4 I need to write a single plot statement, which creates 4 plots (for x1, x2, x3 and x4) in the graphics window, without using 'for' loop. Is this possible? Does 'do.call' help in this context? Or do I have any option in the 'plot' statement itself to do this? Thanks in advance, Shubha This

Hello: I'm reading in a series of text files (100 files that are each 2000 rows by 6 columns). I wish to combine the columns (6) of each file (100) and get the row mean. I'd like to end up with a data.frame of 2000 rows by 6 columns. foo <- list() for(i in 1:10){ # The real data are read in from a series of numbered text files foo[[i]] <- data.frame(x1 = rnorm(100), x2 =

Hi all, I have the following x1<-paste("A", 1:6, sep = "") x2<- round(rgamma(6,2,1)) x3<-paste("B", 1:6, sep = "") x4<- round(rgamma(6,2,1)) data1 <- data.frame(x1,x2,x3,x4) I would like to get data2 <- c(A1=4, A2=1, A3=0,...) Is there any standard for such a case? Thank you very much in advance, Diego

Dear R users, I?m a graduate students and in my master thesis I must obtain the values of the parameters x_i which maximize this Multinomial log?likelihood function log(n!)-sum_{i=1]^4 log(n_i!)+sum_ {i=1}^4 n_i log(x_i) under the following constraints: a) sum_i x_i=1, x_i>=0, b) x_1<=x_2+x_3+x_4 c)x_2<=x_3+x_4 I have been using the ?ConstrOptim? R-function with the instructions

I'm pasting below a working R file featuring a function I'd like to polish up. I'm teaching regression this semester and every time I come to something that is very difficult to explain in class, I try to simplify it by writing an R function (eventually into my package "rockchalk"). Students have a difficult time with predict and newdata objects, so right now I'm