similar to: creating a certain type of matrix

Displaying 20 results from an estimated 20000 matches similar to: "creating a certain type of matrix"

2006 Feb 07
1
(second round) creating a certain type of matrix
Hi R users Here is what I got with help from Petr Pikal (Thanks Petr Pikal). I modified Petr Pikal's code to a little to meet my purpose. I created a function to generate a matrix generate.matrix<-function(n.variable) { mat<-matrix(0,n.variable,(n.variable/2)/5+1) #matrix of zeroes dd<-dim(mat) # actual dimensions mat[1:(dd[1]/2),1]<-1 #put 1 in first half of first column
2006 Nov 06
3
CPU or memory
Hi R users Having both a faster CPU and more memory will boost computing power. I was wondering if only adding more memory (1GB -> 2GB) will significantly reduce R computation time? Taka, _________________________________________________________________ Get FREE company branded e-mail accounts and business Web site from Microsoft Office Live
2006 Jun 27
3
looking for a more efficient R code.
Dear R-users I have four simple linear models, which are all in the form of a*X+b The estimated parameter vectors are a <- c(1,2,3,4) b <- c(4,3,2,1) My goal is to draw a plot where x-axis is X (range from -100 to 100) and y-axis is the sum of all four linear models X <- seq(-100,100, length=10000) plot(X, sum of the four linear functions) I started with a function for summing
2006 Jun 30
2
incomplete final line found by readLines on ...
Dear R-users I need to read some text files produced by some other software. I used readLines (with n = -1 ) command and then tried to find some numbers I liked to extract or some line numbers I like to know. The problem is that there is no empty line at the end of the text files. R gave me this warning below; In addition: Warning message: incomplete final line found by readLines on
2006 Jul 11
2
0* log(0) should be zero but NaN
Dear R-users >prob <- c(0.5,0.4,0.3,0.1,0.0) >cal <- prob * log(prob,base=2) >cal [1] -0.5000000 -0.5287712 -0.5210897 -0.3321928 NaN Is there any way to change NaN to zero ? I did come up with this by applying Ripley's relpy to my previous question cal <-prob*log(pmax(prob,0.00000001),base=2) Any suggestion ? Thank you Taka
2007 Jun 01
2
scan a directory and then make a string vector consisting of file names
Dear R-users, I am looking for a way to scan a directory and then make a string vector consisting of the file names in the directory. For example, under c:\temp\ there are 4 files a.txt, b.txt, c.txt, and d.txt I would like to have a string vector c("a.txt","b.txt","c.txt","d.txt") How do I do that? Thanks Taka,
2006 Sep 24
2
s language version and complie languages
Hi R users Which version of S does the current R version use? Venables and Ripley's book (2000) says R is version 3 of S language. Is there any change since 2000 ? I searched R-help archive for using C or C++ with R. Although there are some postings, I am looking for up-to-date answers. Which one ( C and C++) works better with R? What complier is the best suited for R ( gcc or visual
2006 Sep 19
2
looking for some functions to analyze a data set.
Hi R-users I have a data set. There are 10 products and the numbers of people who ranked the products. The format of the data set is productID rank1 rank2 rank3 rank4 rank5 rank6 rank7 rank8 rank9 rank10 ------------------------------------------------------------------------------------------------------- 1 10 2 3 3 6 4 2 5
2006 Feb 05
3
reading in a tricky computer program output
Hi R user I need to read in some values from a computer program output. I can't change the output format because the developer of the program doesn't allow to change the format of output. There are two formats. First one looks like this if I have 10 variables, ------------------------------------------------------------------------------------------------------ [ 1]
2006 Aug 10
2
index.cond in xyplot
Dear R-users I have 5 dependent variables (y1 to y5) and one independent variable (x) and 3 conditioning variables (m, n, and 0). Each of the conditioning variables has 2 levels. I created 2*4 panel plots. xyplot(y1+y2+y3+y4+y5 ~ x | m*n*o,layout = c(4,2)) I would like to reorder the 8 panels. I tried to use index.cond (e.g., index.cond = list(c(1,3,2,4,5,7,6,8)) but it didn't work out.
2006 Jan 27
3
[Q] extracting lower diagonal elements of a matrix
Hi R users I like to extract lower diagonal elements of a matrix in such a way like, data[1,2], data[1,3], ...., data[5,6] are extracted from a matrix called 'data' This short script below is what I have written so far. ########################################## data <- matrix(rnorm(36,0,1),nrow=6) temp<-c() for (i in 1:(nrow(data)-1)) { for (j in (i+1):nrow(data)) {
2006 Feb 05
2
generating strings in a tricky order
Hi R users I like to generate some strings (a character vector) in a special way like If i have 5 variables "002.001", "003.001", "003.002", "004.001", "004.002", "004.003", "005.001", "005.002", "005.003", "005.004" so the created string vector's elements are "002.001",
2006 Feb 08
3
difference between rnorm(1000, 0, 1) and running rnorm(500, 0, 1) twice
Hi R users This looks a simple question Is there any difference between between rnorm(1000,0,1) and running rnorm(500,0,1) twice in terms of outcome ? TM
2006 Feb 14
2
combine elements of a character vector into a character
Hi R users I have a simple question to ask x <- c("a","b","c") x [1] "a" "b" "c" I like to have "abc" instead of having "a" "b" "c" I tried to use paste and other functions related to character. Is there any function (command) that enable me to combine elements of a character vector into
2006 Feb 18
2
figure out whether 1 is between two numbers
Hi R users I have two variables (X and Y) X <- rnorm(100,.7,.5) Y <- rnorm (100,.3,.1) I like to know whether 1 is between each pair of X and Y or not. Thanks TM
2006 Feb 04
2
saving a character vector
Hi R users I wrote a function that generates some character strings. generate.index<-function(n.item){ for (i in 1:n.item) { for (j in ((i+1):n.item)) { cat("i",formatC(i,digits=2,flag="0"),".",formatC(j,digits=2,flag="0"),"\n",sep="") } } } I
2006 Feb 17
2
creating 3-way tables for mantelhaen.test
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
2006 Jul 10
2
problem in my code
Dear R-users I wrote a small program for assigning a membership Here is my script sample.size <- 60 x <- rnorm(sample.size, 0, 1) y <- rnorm(sample.size, 0, 1) x.mean <- mean(x) y.mean <- mean(y) membership <- numeric(sample.size) for (i in 1:sample.size) { if ((x[i] < x.mean) && (y[i] < y.mean)) { membership[i]
2006 Jun 30
1
apply a function to several lists' components
Dear R-user I have 100 lists. Each list has several components. For example, >data1 $a [1] 1 2 $b [1] 3 4 $c [1] 5 There are data1, data2,...., data100. All lists have the same number and the same name of components. Is there any function I can use for applying to only a specific component across 100 lists? (e.g., taking mean of $c acorss 100 lists) or do I need to write my own
2007 Jun 29
1
extracting df and MS values from aov
Dear R users, I would like to extract df and Mean Sq values. I tried several things (e.g., str(model1), names(model1)) but I can't find a way to extract these values. I also tried to search using RSiteSearch. Any help will be appreciated. Thanks Taka, model1<-aov(dv~iv.1*iv.2*iv.3) summary(model1) Df Sum Sq Mean Sq iv.1 1 3.200 3.200