Displaying 17 results from an estimated 17 matches for "manliyanrhelp".
2009 Mar 04
5
how to create many variables at one time?
Hi:
I need to create many variables at one time,how to do this in R?
for eg ,X1,X2.......X100?
Thanks~
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2008 Jun 04
3
create many variables at one time~
I need to create 100 variable ,whose name is id.1,id.2~~~~id.100
then I need to let a vector say id<-c(id.1,id.2....id.100)
any easy way to do this?
thanks a lot~
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2008 Jun 19
1
try to find the MLE of a function
Hi everyone:
I have a density function f(x|theta)=theta*x^(theta-1),where
0<x<1,0<theta<infinite
I want to pratice on R to find the MLE of this function,here is my code:
x <- (0:10)/10
f<-function(theta) prod(theta*x^(theta-1))
mle(f)
and r gave me :Error in eval(expr, envir, enclos) : argument is missing,
with no default
what mistake I just made?and how to add a
2008 Jun 04
2
linear model in the repeated data type~
here is the data:
y<-c(5,2,3,7,9,0,1,4,5)
id<-c(1,1,6,6,7,8,15,15,19)
t<-c(50,56,50,56,50,50,50,60,50)
table1<-data.frame(y,id,t)//longitudinal data
what I want to do is to use the linear model for each id ,then get the
estimate value,like:
fit1<-lm(y~t,data=table1,subset=(id==1))
but ,you can see the variable "id" is quite irregular,they are not arranaged
in order
2008 Jun 04
1
how to extract a specific group of data from a table?
a table with three varialbe:treatment
(low,high),size(large,small),response y
I want all response y with treatment=low and size=large,
I try to write as :
treatment<-c("low","low","high","high")
size<-c("small","large","small","large")
y<-c(1,2,4,5)
table1<-data.frame(treatment,size,y)
2008 Jun 04
1
linear model with the repeated data type~
here is the data:
y<-c(5,2,3,7,9,0,1,4,5)
id<-c(1,1,6,6,7,8,15,15,19)
t<-c(50,56,50,56,50,50,50,60,50)
table1<-data.frame(y,id,t)//longitudinal data
the above is only part of data.
what I want to do is to use the linear model for each id ,then get the
estimate value,like:
fit1<-lm(y~t,data=table1,subset=(id==1))
but ,you can see the variable "id" is quite
2008 Jun 18
3
multiple multiplication in R
hi: just a very simple quesion,how to do multiple multiplication in R
x<-c(1,2,3,4,5,6)
how to get 1*2*3*4*5*6?
I checked the Arithmetic Operators in R,but did not found the operators
for this function,anyway can do this except the loop?
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2008 Jun 05
1
quite complicated case(the repeated data arranage~)
Hi everyone:
I have been struggling with this repeated data type for whole afternoon,I
sent two emails to server for help,many people kindly responded , hereby
thank you so much,but since I dont want to write to much in email,so I
divide the problem in parts,so far this seem did not work out very well,so
this is my whole problem~
first I have example of data here:
2009 Mar 10
5
Cholesky Decomposition in R
Hi everyone:
I try to use r to do the Cholesky Decomposition,which is A=LDL',so far I
only found how to decomposite A in to LL' by using chol(A),the function
Cholesky(A) doesnt work,any one know other command to decomposte A in to
LDL'
My r code is:
library(Matrix)
A=matrix(c(1,1,1,1,5,5,1,5,14),nrow=3)
> chol(A)
[,1] [,2] [,3]
[1,] 1 1 1
[2,] 0 2 2
2008 Jun 04
1
column and row
<-fit1$coefficients
y.control y.low y.high
(Intercept) 19.628713 21.883999 20.023814
log(1 + (age - 45)/10) -7.383725 -6.017342 -5.084431
here is my outcome,I need one vector say b1=first row without the intercept
,like:(19.628713, 21.883999, 20.023814)
and another b2=second row without the log(1 + (age - 45)/10),only the
data,how to do this in R?
2008 Jun 05
1
sorting the data~
id<-c(1,1,1,1,3,3,3,7,7,7,7,11,11,11........)
how to sort this kind of data to
id:(1,1,1,1,2,2,2,3,3,3,3,4,4,4.........)
thanks~
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2008 Jun 17
0
some r code for linear mixed model
Hello everyone:
I have some quesions about the R code for linear mixed model,hope some one
can give me some hints,thanks a lot~
Say:
we have A B C three factors
(i)A is fixed ,B and C are random,and B is nested in C,so the R code for
this case would be:
case1<-lme(y~A+B+C+......,random=~B|C)
where "B|C" actually mean B is nested in C, is it correct?
(ii)and if I update
2009 Mar 11
0
anyone can help me with Cholesky Decomposition
Hi:
what I want to do is decompose the a symmetric matrix A into this form
A=LDL'
hence TAT'=D,T is inverse of (L)and T is a lower trangular matrix,and D is
dignoal matrix
for one case
A=1 1 1
1 5 5
1 5 14
T=inverse(L)= 1 0 0
-1 1 0
0 -1 1
D=(1,4,9)
I tried to use chol(A),but it returns only trangular, anyone know
the function can return
2009 Aug 20
3
how to categorize continuous variable when useing regression
assume dependent variable y( continuous),independent variable x (
continuous),I try to categorize x with some interval,such that,those
intervals would has most significant different effect on y.
any one knows which method I should apply,I really need some hints,thanks
so much~
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2009 Mar 06
3
how to omit NA without using ifelse
I have a 50*50 matrix,some entry are NAs,I want to replace these NA by
0,so can I use some syntax to do so other than using ifelse?
I tried to use replace(a,NA,0),it didnt work~~(a is matrix name)
Thanks~
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2008 Jun 23
1
problem in R for Linear mixed model~
Dear R users:
I just got confused some R code used in linear mixed model~
example,two factors,A, B,C,A is fixed ,B,C are random,and B is nested in
C,if I wannt to use linear mixed model,are the following code correct for
each case?
case1:want to know random effect of B,
case1<-lme(y~A*B*C,random=~B|C) where "B|C" stand for what?,mean B is
nested in C?
case2: how to wirte
2009 Apr 11
2
who happenly read these two paper Mohsen Pourahmadi (biometrika1999, 2000)
http://biomet.oxfordjournals.org/cgi/reprint/86/3/677 biometrika1999
http://biomet.oxfordjournals.org/cgi/reprint/94/4/1006 biometrika2000
Hi All:
I just want to try some luck.
I am currenly working on my project,one part of my project is to
reanalysis the kenward cattle data by using the method in Mohsen's paper,but
I found I really can get the same or close output as he did,so,any