Displaying 20 results from an estimated 288 matches for "xa".
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2012 Feb 09
1
Constraint on one of parameters.
...r a set of parameters and want to set a
constraint on only one parameter. Here is my function. What I want to do is
estimate the parameters of a bivariate normal distribution where the
correlation has to be between -1 and 1. Would you please advise how to
revise it?
ex=function(s,prob,theta1,theta,xa,xb,xc,xd,t,delta) {
expo1= exp(s[3]*xa+s[4]*xb+s[5]*xc+s[6]*xd)
expo2= exp(s[9]*xa+s[10]*xb+s[11]*xc+s[12]*xd)
expo3= exp(s[15]*xa+s[16]*xb+s[17]*xc+s[18]*xd)
expo4= exp(s[21]*xa+s[22]*xb+s[23]*xc+s[24]*xd)
expo5= exp(s[27]*xa+s[28]*xb+s[29]*xc+s[30]*xd)
nume1=prob[1]*(s[2]^-s[1]*s[1]*t^(s[1]-1)*...
2011 Aug 15
2
plotting segments only and in color
Hello,
I've a question concerning the display of interval data.
A sample dataset where X is an interval between Xa and Xb
which should be displayed:
Y=c(15,14,23,18,19,9,19,13)
Xa=c(17,22,21,18,19,25,8,19)
Xb=c(22,22,29,34,19,26,17,22)
X = (Xa+Xb)/2
It's easily possible to plot the mean of the interval like:
plot(X,Y)
afterwards I can create lines for the interval with:
segments(Xa,Y,Xb,Y)
I think that...
2007 Dec 17
0
guidelines for consistency of vector functions
...ce of software that
was carefully engineered for widespread use.)
All of the above is a rough draft that could be discussed further (e.g.,
should '[.<-' go in level 1 or level 2?) if there was any interest in
pursuing this suggestion.
Comments?
-- Tony Plate
PS:
Here's a few examples of running an automatic vector-functionality
tester on some vector-like classes in R ("basic"="level 1",
"extra"="level 2", and "bonus"="level 3" functions) (this might be hard
to read if line wrapping happens -- I've attached...
2011 Mar 06
4
sorting & subsetting a data.frame
...ng alone works fine
with(x, x[Sepal.Length==6.7,])
##sorting alone works fine
with(x, x[order(Sepal.Length, rev(sort(Species1))),])
##gets subsetted, but not sorted as expected
with(x, x[(Sepal.Length==6.7) & order(Sepal.Length, rev(sort(Species1))),])
##gets subsetted, but sorts very strangely
xa <- with(x, x[Sepal.Length==6.7,]); with(xa, xa[order(Sepal.Length,
rev(sort(Species1))),])
xa <- with(x, x[Sepal.Length==6.7,]); with(xa, xa[order(rev(sort(Species1))),])
I've checked The R Inferno, Quick-R and several other places with no
obvious solution.
Any ideas? Regards
Liviu
--...
2007 Oct 13
2
the use of the .C function
...ll rights reserved.
//
// Returns psi function for real argument 'x'.
// NOTE: Returns 1e308 for argument 0 or a negative integer.
//
#include <iostream.h> // or <stdio.h>?
#include <math.h>
#define el 0.5772156649015329
double psi(double x)
{
double s,ps,xa,x2;
int n,k;
static double a[] = {
-0.8333333333333e-01,
0.83333333333333333e-02,
-0.39682539682539683e-02,
0.41666666666666667e-02,
-0.75757575757575758e-02,
0.21092796092796093e-01,
-0.83333333333333333e-01,
0.4...
2011 Nov 22
5
x, y for point of intersection
...this point.
For exemplification consider this:
?
?
set.seed(123)
?
k1 <-rnorm(100, mean=1.77, sd=3.33)
?k1 <- sort(k1)
q1 <- rnorm(100, mean=2.37, sd=0.74)
q1 <- sort(q1, decreasing = TRUE)
plot(k1, q1, xlim <- c((min(k1)-5), (max(k1)+5)),
type="l")
?
ya <- 2
xa = -5
yb=4
xb=12
?
lines(c(xa, xb), c(ya, yb), col = 2)
?
# I want to get the x and y coordinates of the
intersection of the 2 lines ?.
?
m <- (ya-yb)/(xa-xb)
b <- ya-m*xa
ln <- loess(q1~k1)
lines(ln)
?
It is clear that the x, y will satisfy both linear
equations, y = m*x + b a...
2006 Aug 02
1
RE
Hi any,
Can some please detail me the createX command in bayesm package?
To make things easy for you to help me, let me put forward my problem
Suppose I have 3 covariates (say X matrix) and my Y has 3 categories say
(1,2,3). Now from the CreateX I understand that the data matrix say 'Xa' must
be of dimension n* (naxp), where 'na' is the number of variables and 'p' is
the number of categories that Y has and 'n' is the number of observations. Now
the Xa matrix will have 9 columns if I give na=3 and p=3, and 6 columns if I
give na =2 and p=3. I underst...
2009 Mar 20
1
Mean-replacing NAs in a 3d array
Hi all
I have a 3d array containing missing values.
> Xa
, , 1
[,1] [,2]
[1,] 1 3
[2,] NA 4
, , 2
[,1] [,2]
[1,] 5 7
[2,] NA NA
, , 3
[,1] [,2]
[1,] 9 11
[2,] 10 12
I want to replace the missing values with the mean, but the mean of each
'page' in the array (wrong terminology I'm sure). So -...
2011 Oct 10
4
correlation matrix
Hello Gurus
I have two correlation matrices 'xa' and 'xb'
set.seed(100)
d=cbind(x=rnorm(20)+1,
x1=rnorm(20)+1,
x2=rnorm(20)+1)
d1=cbind(x=rnorm(20)+2,
x1=rnorm(20)+2,
x2=rnorm(20)+2)
xa=cor(d,use='complete')
xb=cor(d1,use='complete')
I want to combine these two to get a third matrix which should...
2012 Jul 10
3
fill 0-row data.frame with 1 line of NAs
Dear all
Is there a simpler method to achieve the following: When I obtain an
empty data.frame after subsetting, I need for it to contain one line
of NAs. Here's a dummy example:
> (.xb <- iris[ iris$Species=='zz', ])
[1] Sepal.Length Sepal.Width Petal.Length Petal.Width Species
<0 rows> (or 0-length row.names)
> dim(.xb)
[1] 0 5
> (.xa <- data.frame(matrix(rep(NA, ncol(.xb)), 1)))
X1 X2 X3 X4 X5
1 NA NA NA NA NA
> names(.xa) <- n...
2017 May 30
2
Pseudo-instruction that overwrites its input register
On Tue, 30 May 2017, Nemanja Ivanovic wrote:
> This is typically accomplished with something like PPC's `RegConstraint` and
> `NoEncode`. You can see examples of it that are very similar to what you're after in
> PPC's load/store with update forms (i.e. load a value and update the base register
> with the effective address - these are used for pre-increment loads/stores).
> For example: the definition of LBZU and friends in lib/Targ...
2004 Mar 10
3
converting lists got by tapply to dataframes
I have two lists:
xa <- list( X=c(1,2,3), Y=c(4,5,6), Z=c(7,8,9) )
xb <- with( barley, tapply( X=seq(1:nrow(barley)), INDEX=site
, FUN=function(z)yield[z]))
I can convert xa to a dataframe easily with:
as.data.frame(xa)
But if i try the same with xb I get:
as.data.frame(xb)
Error in as....
2013 Apr 16
1
avoid losing data.frame attributes on cbind()
Dear all,
How should I add several variables to a data frame without losing the
attributes of the df? Consider the following:
> require(Hmisc)
> Xa <- iris
> label(Xa, self=T) <- "Some df label"
> str(Xa)
'data.frame': 150 obs. of 5 variables:
$ Sepal.Length: num 5.1 4.9 4.7 4.6 5 5.4 4.6 5 4.4 4.9 ...
$ Sepal.Width : num 3.5 3 3.2 3.1 3.6 3.9 3.4 3.4 2.9 3.1 ...
$ Petal.Length: num 1.4 1.4 1.3 1.5 1.4 1.7...
2012 Jun 21
4
convert 'character' vector containing mixed formats to 'Date'
..."13/04/2004" "2/5/2005" "2/5/2005" "7/5/2007"
"22/04/2004"
[7] "21/04/2005" "20080430" "13/05/2003" "20080529" NA
NA
[13] "19/05/1999" "17/05/2000" "17/05/2000"
> sum(xa <- grepl('/', x))
[1] 11
> sum(xb <- grepl('200', substr(x, 1,4)))
[1] 2
> sum(xc <- is.na(x))
[1] 2
> x[xa] <- as.Date(x[xa], format="%d/%m/%Y")
> x[xb] <- as.Date(x[xb], format="%Y%m%d")
> x
[1] "12843" "12521"...
2009 Nov 25
1
group generics
...lasses A and B, where B contains A. In the implementation of
the group generic for B I would like to use the corresponding group
generic for A. Is there a way to do that?
I would also appreciate any comments if what I'm trying to do seems like
the wrong approach.
Here's a stripped down example:
setClass("A",
representation=representation(xa="numeric")
)
setMethod("Arith", signature(e1="numeric", e2="A"), function(e1, e2) {
new("A", ax=e1*e2 at xa)
}
)
setClass("B",
represent...
2011 Dec 07
4
bug in rank(), order(), is.unsorted() on character vector
Hi,
This looks OK:
> x <- c("_1_", "1_9", "2_9")
> rank(x)
[1] 1 2 3
But this does not:
> xa <- paste(x, "a", sep="")
> xa
[1] "_1_a" "1_9a" "2_9a"
> rank(xa)
[1] 2 1 3
Cheers,
H.
> sessionInfo()
R version 2.14.0 (2011-10-31)
Platform: x86_64-unknown-linux-gnu (64-bit)
locale:
[1] LC_CTYPE=en_CA.UTF-8 LC_NUMERIC=C...
2013 Jul 16
2
Problem following an R bug fix to integrate()
...other systems):
> fn <- function(x, y) ifelse(x^2 + y^2 <= 1, 1 - x^2 - y^2, 0)
> tol <- 1.5e-8
> fy <- function(x) integrate(function(y) fn(x, y), 0, 1,
subdivisions = 300, rel.tol = tol)$value
> Fy <- Vectorize(fy)
> xa <- -1; xb <- 1
> Q <- integrate(Fy, xa, xb,
subdivisions = 300, rel.tol = tol)$value
Error in integrate(Fy, xa, xb, subdivisions = 300, rel.tol = tol) :
roundoff error was detected
Obviously, this realizes a double integration, split up into two 1-dimensio...
2007 Jul 04
1
Calling C Code from R
...eb)
Statistician
NSW Department of Commerce
Sydney, Australia
testCX1.C
--------------
/*
*********************
testCX1.c
*********************
*/
#include <R.h>
#include <Rdefines.h>
#include <Rmath.h>
SEXP testC1(SEXP a)
{
int i, nr;
double *xa, *xw, tmp;
SEXP w;
PROTECT(a = coerceVector(a, REALSXP));
nr = length(a);
printf( "Length : %d \n", nr);
PROTECT(w = allocVector(REALSXP, 1));
xa = REAL(a);
xw = REAL(w);
tmp = 0.0;
for (i = 0; i < nr; i++)
{
tmp += xa[...
2011 Jul 28
1
Regression with ranges and displaying them in an XY-Plot
Hello UseRs,
I've got 3 variables, the dependent variable Y as well as a max and a min value of the independent variable (Xa and Xb) where in some cases Xa=Xb (so actually a single value for X).
First I'd like to perform a regression, but my problem is that my X is a range (acutally a censored independent variable Xa-Xb) rather then one single value. I know already some possible approaches like Bayesian Regression or...
2006 Oct 02
0
Arrowheads at line-ends
...ows, but this solution
appears too be quite inflexible.
So my question to the more experienced R-users out there is if there
is a smarter way to do this? Is there, for instance, any graphing
property that automaticly insert arrowheads?
Here's the code of my "manual" solution:
xA <- c(0.0000,0.0968,0.2340,0.4645,0.6115,0.8890,1.0000)
Va <- c(69.016,69.769,70.775,72.456,73.280,73.564,73.921)
Vb <- c(18.020,17.822,17.480,16.897,16.277,13.833,13.101)
plot(c(0,1), c(10,80),
type="n",
xlab=expression(x[aceton]),
ylab="Partielt molart volum",
bty...