similar to: optimize

Does anyone know of a method that I can get the intersection where the red and blue curves meet i.e. the value on the x-axis? x <- 1:10 y <- 10:1 plot(x,y) abline(lm(y~x),col="blue") abline(h=2.5,col="red") Muhammad

Hi all, I'm plotting to get the intersection value of three curves. Defining the x-axis as dsm, the following code works; dsm = c(800,600,NA,525,NA,450,400,NA,NA,NA,0) s3 = seq(0.05,1.05,0.1) plot(dsm,s3,col="blue",las=1,ylab="fraction",xlab="distance (km)") fc <- function(x,a,b){a*exp(-b*x)} fm <- nls(s3~fc(dsm,a,b),start=c(a=1,b=0)) co <- coef(fm)

Hi all, I have the following script which fills the values which are less than the mean of a given timeseries. If you look closely, the colored regions are "out of line". Any suggestions how I can rectify this? Thanks Muhammad # ----- #rm(list=ls()) x <- abs(rnorm(100)) tt <- 1:100 m <- mean(x) w <- which(x>=m) x1 <- x ; x2 <- x ; x3 <- x x1[w] <- m

Hello R-users, I would like to know how to find the standard deviation for each element in a set of matrices. Given the following files, File1 File2 File3 1 1 1 4 4 4 7 7 7 2 2 2 5 5 5 8 8 8 3 3 3 6 6 6 9 9 9 I want to calculate the standard deviation for every cell in the file (I'm using gridded data). The desired output is Output 3 3 3 3 3

Hi all, Given the following, > xx [[1]] V1 V2 V3 [1,] 1 2 3 [2,] 4 5 6 [3,] 7 8 9 [[2]] V1 V2 V3 [1,]10 11 12 [2,]13 14 15 [3,]16 17 18 [[3]] V1 V2 V3 [1,]19 20 21 [2,]22 23 24 [3,]25 26 27 how do i extract elements in each file so that after transpose, it looks something like the following; 1 10 19 2 11 20 3 12 21 and so on.. Thanks.. -- Muhammad

Hi useRs, I ran into an inconsistent output problem again. Here is the simplify illustration I've got a matrix as follows > x V1 V2 V3 [1,] 1 2 3 [2,] 4 5 6 [3,] 7 8 9 Associated with the matrix is a scaling factor, sca, derived from, say the mean of the respective columns, V1-V3; > sca V1 V2 V3 2.5 1.7 3.6

Hello useRs, I'd like to perform a moving average on the dataset, xx. I've tried combining the functions Reduce and rollmean but it didn't work. > r <- function(n) rollmean(n, 2) # where 2 = averaging interval > output < - Reduce("r", x) Error in f(init, x[[i]]) : unused argument(s) (x[[i]]) Is there anything wrong with the code in the first place? where

Hi all, I'm trying to get the min and max of a sequence of number using a loop like the folllowing. Can anyone point me to why it doesn't work. Thanks. type <- c("min","max") n <- 1:10 for (a in 1:2) { print(type[a](n)) } -- Muhammad

Hi, Can someone advise why the followind did not produce the array, given the condition specified? s <- 1 a1 <- array(dim=c(1,4)) a2 <- array(dim=c(2,4)) arr <- ifelse(s==0,a1,a2) Thanks. Muhammad

Dear all, I'm trying to make an R code for the drought severity index (DSI) developed by Philips and McGregor (1998). You can refer to the description of the algorithm on page 19 from http://dissertations.port.ac.uk/229/01/MaloneS.pdf The code is given in Excel as the following and can be found on page 60 from the same link. C7 = IF(C6<0,IF(@SUM(A6:A1)<0,C6+A6,"0"),

useRs, I'm getting limited success in trying to apply increment in a loop. The following defined function creates a +1 increment incr <- function(x){ eval.parent(substitute(x <- x + 1)) print(x) } How do I apply it in a loop on my test dataset, x1, so that the procedure becomes x1[c(1:2)] x1[c(2:3)] x1[c(3:4)] where x1 = > m <- matrix(1:3,3,3) > x1 <- list(m, m+1,

Hi all, I would like to get the array index for a range of values, say 0 < x < 1.5. I'm wondering if there is an alternative for the following which I've done x0 <- rnorm(100) x1 <- ifelse(x0 > 0 & x0 < 1.5,"t","f") x2 <- which(x1=="t",arr.ind=TRUE) x0[x2] Thanks. -- Muhammad

Dear all, I'm having issues with the installation of the ncdf package. It returns a non-zero exit status. Can anyone suggest what I should do next? FYI, I do not have problems installing other packages. Thanks. Muhammad * installing *source* package ?ncdf? ... checking for nc-config... /usr/local/bin/nc-config configure: creating ./config.status config.status: creating src/Makevars **

Hi all, I have a list of 20000 data, and the list look like below. I wonder what is the simplest way to extract 'kappa' value (or 'xi' or 'alpha' for the matter) from each of the data. How can I simply code it without having to change the list to a dataframe first? Many thanks! $X19997 xi alpha kappa 784.7718640 165.4065141 -0.2709599 $X19998

Hello, I want the ouput to take the name of the original file. I have the following code - but the problem is that the output overrides the original file which I desire not. So given an input file called File1.txt, I want the ouput to be called File1.out.txt, or something along this line. I'm working with many files, fyi. out=c("file1.txt", "file2.txt",

Hello all, I'm trying to create a 2x2 matrix, 32 times after unlist() so that I can convert the list to matrix. I've looked through the R archive but couldn't find the answer. There is what I've done. > f <- system("ls *.txt", intern=TRUE) > x <- lapply(f, read.table) > x [[1]] V1 V2 1 -27.3 14.4 2 29.0 -38.1 [[2]] V1 V2 1 14.4

Hi all, I have a file, say, test.txt, which contains the following information. I'm trying to read in the file and specifying the missing values as NA so that each column has the same number of rows. I've tried all sorts of manipulation but to no avail. r1 r2 r3 1 3 2 3 3 2 3 4 2 3 5 2 3 6 2 3 7 2 8 2 9 2 3 The output should be r1 r2 r3 1 NA 3 2 NA 3 3 2 3 4 2 3 5 2 3 6 2 3 7 2

Dear R-users, I'd like to perform arithmetic functions on 1000 files containing a 2000x2000 matrix. Can anyone advise? For example, File1 File2 Output 1 1 1 4 4 4 5 5 5 2 2 2 + 5 5 5 = 7 7 7 3 3 3 6 6 6 9 9 9 Muhammad -- Muhammad Rahiz | Doctoral Student in Regional Climate Modeling Climate Research

Hi all, How can I overcome the error "object of type 'closure' not subsettable" I ran the following script seq <- paste(seq(1914, 1916, by=1), "*.y", sep=".") # make sequence c <- 3 # total number of files d2 <- file # creates dummy file # Input sequence in loop for (i in 1:3){ list <- list.files("~/ukcp09/txt/x.djf", seq[[i]]) file

Dear useRs, I'm having a slight problem with plotting on 2 axes. While the following code works alright on screen, the saved output does not turn out as desired i.e. the secondary y-axis does not display fully. Just run the code and look at image output. Suggestions please... thanks, Muhammad --- rm(list=ls()) x <- 1:100 y <- 200:300 par(mar=c(5,5,5,7)+0.1) # inner margin