Displaying 20 results from an estimated 10000 matches similar to: "help with simple function"
2006 Mar 10
1
what's wrong with my "cov"?
Hi all,
Why cov(y, y) only gives one value, and cov(t(y), t(y)) gives 3x3 NA matrix?
Here my y is listed below and it is a 3x1 matrix.
I am expecting that if I have a random vector y=[y1 y2 y3]', here " ' "
denotes a transposition so that
y is a column vector, where y1, y2, y3 are independent random variables...
then cov(y, y) should be
E[ y * y' ] - E[y] * E[y] ',
2008 Feb 15
1
Questions about EM algorithm
Dear all:
Assume I have 3 distributions, x1, x2, and x3.
x1 ~ normal(mu1, sd1)
x2 ~ normal(mu2, sd2)
x3 ~ normal(mu3, sd3)
y1 = x1 + x2
y2 = x1 + x3
Now that the data I can observed is only y1 and y2. It is
easy to estimate (mu1+m2), (mu1+mu3), (sd1^2+sd2^2) and
(sd1^2+sd3^2) by EM algorithm since
y1 ~ normal(mu1+mu2, sqrt(sd1^2+sd2^2)) and
y2 ~ normal(mu1+mu3, sqrt(sd1^2+sd3^2))
However, I want
2008 May 24
2
Importing data in text file into R
Dear all,
I am quite new to R; facing certain problems:
Say, I have a text file( named as "try"):
Year C1 C2 C3 C4 C5 C6
Y1 3.5 13.8 9.5 6.8 0.4 24.2
Y2 3.8 13.9 9.9 7.6 0.7 12.8
Y3 4.5 14.5 14.2 9.2 0.6 14.5
Y4 5.9 16.2 24.6 12.7 0.2 24.3
Y5 7.2 20.4 40.6 18.2 0.8 28.2
Y6 5.9 18.6 37.4 14.5 0.3 36.9
Y7 8.0 16.1 88.6 24.1 0.1 34.6
Y8 13.6 21.1 56.3 19.0 0.7 33.3
I wish to import the
2013 Jan 14
1
Confidence intervel for regression line
Hi all,
For the simple linear regression, I want to find the input "x" value so
that the
lower confidnece limit is a specific number, say 0.2.
In other words, I want to find the value of x so that the lower
confidence bound crosses the horizontal line 0.2.
Is there a simple way (an R function) that can do this?
Thanks.
Hanna
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2011 Nov 05
1
acf?
I started to check what I thought I knew with autocovariance and it doesn’t
jive with the the calculations given by ‘R’. I was wondering if there is
some scaling or something that I am not aware of.
Take the example
Ø d <- 1:10
Ø (a <- acf(d, type="covariance", demean=FALSE, plot=FALSE))
Autocovariances of series ‘d’, by lag
0 1 2 3 4 5 6
2008 Jul 08
1
aggregate() function and na.rm = TRUE
All,
I've been using aggregate() to compute means and standard deviations at
time/treatment combinations for a longitudinal dataset, using na.rm = TRUE
for missing data.
This was working fine before, but now when I re-run some old code it isn't.
I've backtracked my steps and can't seem to find out why it was working
before but not now. In any event, below is a reproducible
2007 Jul 13
2
nearest correlation to polychoric
Dear all,
Has someone implemented in R (or any other language)
Knol DL, ten Berge JMF. Least-squares approximation of an improper correlation matrix by a proper one. Psychometrika, 1989, 54, 53-61.
or any other similar algorithm?
Best regards
Jens Oehlschl?gel
Background:
I want to factanal() matrices of polychoric correlations which have negative eigenvalue. I coded
Highham 2002
2014 Nov 05
3
Agregar ruido a una serie de tiempo
Bueno, realmente no es necesaria que la serie esté centrada en este caso, ya que estoy sumando un ruído blanco
Un saludo
From: fjroar en hotmail.com
To: caaperezan en gmail.com; r-help-es en r-project.org
Date: Wed, 5 Nov 2014 13:00:49 +0000
Subject: Re: [R-es] Agregar ruido a una serie de tiempo
Hola buenos d?as:
Yo cuando he tenido que hacer estos trabajos, lo que hac?a era coger la serie
2008 Jan 29
3
How to get two y-axises in a bar plot?
Hi,
I have measured two response variables (y1, y2) at each treatment level
(x = 0, 1.5 or 3). Now I would like to show the y1 and y2 against x in a
bar plot. However, y1 and y2 differ in scale so I need two y-axises, one
on the left side and one on the right side (and I dont want to
standardize my responses). This is fairly easy if you want to show
points,lines etc, but gets more complicated
2011 Nov 26
2
simplify source code
Hi
I would like to shorten
mod1 <- nls(ColName2 ~ ColName1, data = table, ...)
mod2 <- nls(ColName3 ~ ColName1, data = table, ...)
mod3 <- nls(ColName4 ~ ColName1, data = table, ...)
...
is there something like
cols = c(ColName2,ColName3,ColName4,...)
for i in ...
mod[i-1] <- nls(ColName[i] ~ ColName1, data = table, ...)
I am looking forward to help
Christof
2003 Mar 04
4
writing several command line in R console
Hi R lovers
I would like to know how to step to the next line in the R console editor
without breaking the continuity of my code
more clearly : if for example I write a function, so far i have to write the
all code inside on the same line wich may become obscure as the function is
more and more complex.
I would like to do like in the example of the manuels:
>twosam <- function(y1, y2) {
2008 Feb 27
4
plot y1 and y2 on one graph
Dear all
I have a code like
x<-1:10
y1<-x+runif(10)*2
y2<-seq(0,50,length.out=10)+rnorm(10)*10
par(mfrow=c(1,2))
plot(y1~x)
plot(y2~x)
Now I would like to plot y1 and y2 on the same graph, with its two scales
(y1 on left and y2 on rigth side).
Any help are welcome.
Kind regards
Miltinho
Brazil
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2007 Jan 30
2
Rbind for appending zoo objects
Hi R,
y1 <- zoo(matrix(1:10, ncol = 2), 1:5)
colnames(y1)=c("a","b")
y2 <- zoo(matrix(rnorm(10), ncol = 2), 6:10)
colnames(y2)=c("b","a")
> y1
a b
1 1 6
2 2 7
3 3 8
4 4 9
5 5 10
> y2
b a
6 0.9070204 0.3527630
7 1.2405943 0.8275001
8 -0.1690653 -0.1724976
9 -0.6905223 -1.1127670
10
2011 Jan 19
2
Reshape
Hi - I'm up against a complicated reshape problem. I have data of the form
X1,Y1,hr1,hr2,hr3
X1,Y2,hr1,hr2,hr3
X1,Y3,hr1,hr2,hr3
X2,Y1,hr1,hr2,hr3
X2,Y2,hr1,hr2,hr3
X2,Y3,hr1,hr2,hr3
where X and Y are factors and the hr(1,2,3) are values. I need it as
,X1, X2
Y1,hr1,hr1
Y1,hr2,hr2
Y1,hr3,hr3
Y2,hr1,hr1
Y2,hr2,hr2
Y2,hr3,hr3
..,
Any hints? I've been at it for hours.
p
--
View
2011 Aug 15
1
update() ignores object
Hi all,
I'm extracting the name of the term in a regression model that
dropterm specifies as the least significant one, and I'm assigning
this name to an object. However, when I use update(), it ignores this
object. Is there a way I can make it not ignore it? A reproducible
example is below:
> lm(x1~1+y1*y2+y3+y4,data=anscombe)->my.lm
>
2006 Mar 10
1
add trend line to each group of data in: xyplot(y1+y2 ~ x | grp...
Although this should be trivial, I'm having a spot of trouble.
I want to make a lattice plot of the format y1+y2 ~ x | grp but then fit a
lm to each y variable and add an abline of those models in different colors.
If the xyplot followed y~x|grp I would write a panel function as below, but
I'm unsure of how to do that with y1 and y2 without reshaping the data
before hand. Thoughts
2013 Apr 08
3
Reshaping a table
Hello all,
I have data in the form of a table:
X Y1 Y2
0.1 3 2
0.2 2 1
And I would like to transform in the form:
X Y
0.1 Y1
0.1 Y1
0.1 Y1
0.1 Y2
0.1 Y2
0.2 Y1
0.2 Y1
0.2 Y2
Any ideas how?
Thanks in advance,
IOanna
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2008 Apr 03
3
summary(object, test=c("Roy", "Wilks", "Pillai", ....) AND ellipse(object, center=....)
Dear All,
I would be very appreciative of your help with the following
1). I am running multivariate multiple regression through the manova() function (kindly suggested by Professor Venables) and getting two different answers for test=c("Wilks","Roy","Pillai") and tests=c("Wilks","Roy",'"Pillai") as shown below. In the
2010 Feb 11
2
Find each time a value changes
Dear List,
I am trying to find each time a value changes in a dataset. The numbers are variables for day vs. night values, so what I am really getting is the daily sunrise and sunset.
A simplified example is the following:
x<-seq(1:100)
y1<-rep(1,10)
y2<-rep(2,10)
y<-c(y1,y2,y1,y1,y1,y2,y1,y2,y1,y2)
xy<-cbind(x,y)
I would like to know each time the numbers change.
Correct
2010 Oct 17
1
lattice xyplot - formatting of multiple Y variables when using subgroups
Hi all,
Using xyplot I want to print to Y variables (y1, y2) versus X, conditional
on the group.
How can I obtain a line (type="l") for one relationship (ie. y1 ~ x) and
points (type="p") for the other (y2 ~ x) ?
library(lattice)
# create some sample data
df<-data.frame(group=as.factor(c(rep("a",4), rep("b",4))), # grouping
variable for conditional