similar to: 3D array

Suppose there are 4 variables d is a function of a , b and c I want to know how a, b and c change will make d change It will be straightforward to see it if we can graph the d surface if d is only a function of a and b, I can use 'persp' to see the surface of d. I can easily see at what values of a and b, d will get the maxium or minium or multiple modes, etc But for 4 dimention graph,

Dear All, I need to perform a numerical integration of one dimensional fucntions. The extrems of integration are both finite and the functions I'm working on are quite complicated. I have already tried both area() and integrate(), but they do not perform well: area() is very slow and integrate() does not converge. Are in R other functions for numerical integration of one dimentional

Hi. I was used to draw 2D plot to show distribution of my samples. It was very powerful in small samples. Recently , I handle a lot of type of samples as more 15. so, I want to use more dimention. I was used that I conduct plsda function and draw biplot, such as, p1=plsda(mw, sp) biplot(p1) How can I draw 3D graph with my data?? I don't know exactly numerical value each spot. please,

I have three column vectors (X1, X2, X3).          X1  X2  X3        20   25  40        100 90  80 I want to put them as one matrix of dimention 2 by 3,  but remove headers(X1,X2,X3) from the matrix. I wrote as follows U<-cbind (X1,X2,X3) the headers are there. I need help please. Thanks Dereje [[alternative HTML version deleted]]

Hi, I would like to write a one-line R code to create a 3-dim array, B, of dimension (n,n,m) from a matrix, A, of dimension (m,n) such that the i-th element of the 3-dim array, B[, , i] is the outer product of the i-th row of A. Thanks for any help, Ravi. [[alternative HTML version deleted]]

Hello, I want to find the roots of an equation in two variables. I am aware of the uniroot function, which can do this for a function with a single variable (as I understand it...) but cannot find a function that does this for an equation with more than one variable. I am looking for something implementing similar to a Newton-Raphson algorithm. Thanks. -- Bill Shipley North American Editor for

Hi, I have a data file, certain lines of which are character fields. I would like to skip these rows, and read the data file as a numeric data frame. I know that I can skip lines at the beginning with read.table and scan, but is there a way to skip a specified sequence of lines (e.g., 1, 2, 10, 11, 19, 20, 28, 29, etc.) ? If I read the entire data file, and then delete the character

Dear R-users I would like to integrate something like \int_k^\infty (1 - F(x)) dx, where F(.) is a cumulative distribution function. As mentioned in the "integrate" help-page: integrate(dnorm,0,20000) ## fails on many systems. This does not happen for an adaptive Simpson or Lobatto quadrature (cf. Matlab). Even though I am hardly familiar with numerical integration the implementation

Dear R users: I'm trying to generate a output file with fixed format using function "sprintf" in R. However, the execution time in R is very long even the toy data (smaller size df) seems to work fine. The syntax that I used is as follows: df.fmt <- sprintf("%2s%2s%2.4f", df$v1, df$v2, df$v3) write.table(df.fmt, output.name,...) The actual dataset is a df with the

Hi, I apologize for this repeat posting, which I first posted yesterday. I would appreciate any hints on solving this problem: I have two matrices A (m x 2) and B (n x 2), where m and n are large integers (on the order of 10^4). I am looking for an efficient way to create another matrix, W (m x n), which can be defined as follows: for (i in 1:m){ for (j in 1:n) { W[i,j] <-

Hi, I would like to solve a system of coupled ordinary differential equations, where there is a delay (time lag) term. I would like to use the "lsoda" function "odesolve" package. However, I am not sure how to specify the delay term using the syntax allowed by odesolve. Here is an example of the kind of problem that I am trying to solve: > library(odesolve)

Hi, Given a positive integer N, and a real number \lambda such that 0 < \lambda < 1, I would like to generate an N by N stochastic matrix (a matrix with all the rows summing to 1), such that it has the second largest eigenvalue equal to \lambda (Note: the dominant eigenvalue of a stochastic matrix is 1). I don't care what the other eigenvalues are. The second eigenvalue is

Dear UseRs!, Everything about UseR! 2010 was terrific! I really mean "everything" - the tutorials, invited talks, kaleidoscope sessions, focus sessions, breakfast, snacks, lunch, conference dinner, shuttle services, and the participants. The organization was fabulous. NIST were gracious hosts, and provided top notch facilities. The rousing speech by Antonio Possolo, who is the chief

Hi, I have noticed that there is a change in the use of ellipses or . in R versions 2.6.1 and later. In versions 2.5.1 and earlier, the . were always at the end of the argument list, but in 2.6.1 they are placed after the main arguments and before method control arguments. This results in the user having to specify the exact (complete) names of the control arguments, i.e. partial matching is

Hi, I would like to know how to capture the console output from running an algorithm for further analysis. I can capture this using capture.output() but that yields a character vector. I would like to extract the actual numeric values. Here is an example of what I am trying to do. fr <- function(x) { ## Rosenbrock Banana function on.exit(print(f)) x1 <- x[1] x2 <- x[2]

Hi, Currently, the "base" has colSums, colMeans. It seems that it would be useful to extend this to also include colMin, colMax (of course, rowMin and rowMax, as well) in order to facilitate faster computations for large vectors (compared to using apply). Has this been considered before? Please forgive me if this has already been discussed before. Thanks, Ravi Ravi Varadhan, Ph.D.

Hi, While using R CMD check I get the following Latex error message which occurs when creating PDF version of manual: LaTex error: File `inconsolata.sty' not found I am using Windows 7 (64-bit) and R 3.0.1. I have MikTex 2.9. I see that the incosolata.sty is present under \doc\fonts folder. How can I eliminate this problem? Thanks, Ravi [[alternative HTML version deleted]]

Hi, I have a right-censored (positive) random variable (e.g. failure times subject to right censoring) that is observed for N subjects: Y_i, I = 1, 2, ..., N. Note that Y_i = min(T_i, C_i), where T_i is the true failure time and C_i is the censored time. Let us assume that C_i is independent of T_i. Now, I would like to generate another random variable U_i, I = 1, 2, ..., N, which is

Hi, I apologize for the previous posting, where the message was not formatted properly. Here is a better version: I have written the following function to check whether a vector has elements satisfying monotonicity. is.monotone <- function(vec, increase=T){ ans <- TRUE vec.nomis <- vec[!is.na(vec)] if (increase & any(diff(vec.nomis,1) < 0, na.rm=T)) ans <- FALSE

Hi, r-gurus: I happened to have a question in my work: I have a dataset, which has only one dimention, like 0.99037297527605 0.991179836732708 0.995635340631367 0.997186769599305 0.991632565640424 0.984047197106486 0.99225943762649 1.00555642128421 0.993725402926564 .... the data is saved in a file called f392.txt. I used the following codes to play around :)