Displaying 20 results from an estimated 10000 matches similar to: "Replicate"
2007 Nov 19
4
sequence of vectors
Dear All,
I wonder if there is any R function to generate a sequence of vectors from existing ones. For example:
x 1<- c(1,2,3)
x2 <- c(4,5)
x3 <- c(6,7,8)
The desired output is a list of all 3*2*3 = 18 possible combinations of elements of x1,x2 and x3. One element for example is (1,4,6).
Many thanks in advance,
Bernard
2005 Oct 06
3
Singular matrix
Dear All,
I have written the following programs to find a non-singular (10*10) covariance matrix.
Here is the program:
nitems <- 10
x <- array(rnorm(5*nitems,3,3), c(5,nitems))
sigma <- t(x)%*%x
inverse <- try(solve(sigma), TRUE)
while(inherits(inverse, "try-error"))
{
x <- array(rnorm(5*nitems,3,3), c(5,nitems))
sigma <- t(x)%*%x
inverse <-
2005 Sep 21
3
Sort a data frame with respect to more than one variable
Dear All,
How can I sort a data frame with respect to more than one variable?
I know that for one variable X one may use: df[order(df$X), ] where df is the data frame containing X.
Many thanks,
Bernard
---------------------------------
[[alternative HTML version deleted]]
2005 Jun 20
2
Data Parsing
Hello. I have looked at R Site Search for this problem, and it didn't
give me exactly what I needed.
Consider this dataset called "results". It has the following information:
Student Day Subject Score
Mary 1 Math Failed
David 2 Science Passed
Bob 4 Reading Passed
Marie 4
2007 Mar 28
2
Standardization Range
? stato filtrato un testo allegato il cui set di caratteri non era
indicato...
Nome: non disponibile
Url: https://stat.ethz.ch/pipermail/r-help/attachments/20070328/ee4422a2/attachment.pl
2006 Mar 06
4
Contingency table and zeros
Hello,
Let's assume I have a vector of integers :
> myvector <- c(1, 2, 3, 2, 1, 3, 5)
My purpose is to obtain the cumulative distribution of these numerical
data, i.e. something like :
value nb_occur.
<=1 2
<=2 4
<=3 6
<=4 6
<=5 7
For this, I create a table with ;
> mytable <- table(myvector)
1 2 3 5
2 2 2 1
However, table() returns an array
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]]
2006 Apr 07
3
strange matrix behaviour: is there a matrix with one row?
Consider this:
> y <- matrix(1:8, ncol=2)
> is.matrix(y[-c(1,2),])
[1] TRUE
> is.matrix(y[-c(1,2,3),])
[1] FALSE
> is.matrix(y[-c(1,2,3,4),])
[1] TRUE
It seems like an inconsistent behaviour:
- with 2 or more rows we have a matrix
- with 1 row we do not have a matrix and
- with 0 rows we have a matrix again
I just stumbled on this behaviour, because I had a problem
with my
2006 May 12
3
Maximum likelihood estimate of bivariate vonmises-weibulldistribution
Thanks Dimitris!!! That's much clearer now. Still have a lot of work to
do this weekend to understand every bit but your code will prove very
useful.
Cheers,
Aziz
-----Original Message-----
From: Dimitrios Rizopoulos [mailto:Dimitris.Rizopoulos at med.kuleuven.be]
Sent: May 12, 2006 4:35 PM
To: Chaouch, Aziz
Subject: RE: [R] Maximum likelihood estimate of bivariate
2008 Apr 09
4
apply lm() for all the columns of a matrix
Hi all,
My question is not really urgent. I can write a loop and solve the
problem. But I know that I'll be in a similar situation many more times so
it would be useful to find out the answer
Is there a fast way to perform linear fit to all the columns of a matrix?
(or in the one dimension of a multi-dimensional array.) I'm talking about
many single linear fits, not about a multiple fit.
2006 Mar 02
2
'...' passed to both plot() and legend()
Dear R-devels,
I'd like to create a plot method for a class of objects that passes
the '...' argument to both plot() and legend(), e.g.,
x <- list(data = rnorm(1000))
class(x) <- "foo"
plot.foo <- function(x, legend = FALSE, cx = "topright", cy = NULL,
...){
dx <- sort(x$data)
plot(dx, dnorm(dx), type = "l", ...)
if (legend)
2005 May 31
1
apply the function "factor" to multiple columns
I have a case where I would like to change multiple columns containing
numbers to factors. I can change each column one at a time as in:
TEMP.FACT$EXPOS01<-factor(TEMP.FACT$EXPOS01,levels=c(1,2,3),labels=c("No
ne","Low Impact","MedHigh Imp"))
TEMP.FACT$EXPOS02<-factor(TEMP.FACT$EXPOS02,levels=c(1,2,3),labels=c("No
ne","Low
2007 May 16
3
more woes trying to convert a data.frame to a numerical matrix
I have the following csv file:
name,x,y,z
category,delta,gamma,epsilon
a,1,2,3
b,4,5,6
c,7,8,9
I'd like to create a numeric matrix of just the numbers in this csv dataset.
I've tried the following program:
sample.data <- read.csv("sample.csv")
numerical.data <- as.matrix(sample.data[-1,-1])
However, print(numerical.data) returns what appears to be a matrix of
2006 Jun 16
3
Vector Manipulation
I have a vector that has 1,974 elements and each element is one of the
following (B, F, N, Y). How do I recreate that vector accept in the
place of N put 0 and in the place of B, F or Y put a 1?
Thanks,
Jacob
[[alternative HTML version deleted]]
2007 May 20
2
Number of NA's in every second column
Hi R-users,
How do I calculate a number of NA's in a row of every second column in my
data frame?
As a starting point:
dfr <- data.frame(sapply(x, function(x) sample(0:x, 6, replace = TRUE)))
dfr[dfr==0] <- NA
So, I would like to count the number of NA in row one, two, three etc. of
columns X1, X3, X5 etc.
Thanks in advance
Lauri
[[alternative HTML version deleted]]
2005 May 19
2
plot question
hi all:
xlim and ylim are used to define the interval limits of a plot. I'm interested in the scale of values between this limits.
suppose xlim=c(0,10)
we can have e.g.
0 5 10
0 2 4 6 8 10
0 1 2 3 4 5 6 7 8 9 10
which is the parameter that allows me to modify this?
thanks in advance
alexandre
2005 Mar 09
1
Flattening a list of data frames
Hello all,
Simple version of my problem:
I've got a list of data frames, where each data frame has the same
number of columns and the same column names. I'd like to flatten the
list into one large data frame. Is there an easy way to do this?
Quick example code:
a <- data.frame(x=c(1,2,3),y=c(5,7,9)
b <- data.frame(x=c(2,4,7,9),y=c(2,3,5,4))
z <- list(a,b)
# Do
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
2007 Jan 21
5
Integration + Normal Distribution + Directory Browsing Processing Questions
Hi everyone,
I am new to R, but it's really great and helped me a lot!
But now I have 2 questions. It would be great, if someone can help me:
1. I want to integrate a normal distribution, given a median and sd.
The integrate function works great BUT the first argument has to be a
function
so I do integrate(dnorm,0,1) and it works with standard m. and sd.
But I have the m and sd given.
2005 Jan 21
2
chi-Squared distribution
Dear Rs:
outer(1:3, 1:3, function(df1, df2) qf(0.95, df1, df2))
I compare this F distribution results with the table, the answers were perfect. But I need to see for chi-sqaured distribution. When I employed the similar formula
outer(1:3, 1:3, function(df1, df2) qchisq(0.95, df1, df2)) , I am getting unexpected results. I need to see the following values:
p=0.750 .....
1 1.323