Displaying 20 results from an estimated 200 matches similar to: "optimization problem"
2008 Nov 03
1
a nlm question
Dear R listers,
I posted this problem several days ago but it seems nobody
answered.
I use nlm to optimize a given function ,but it always generates
the following warnings
"
Error in nlm(foo, theta.start) : non-finite value supplied by 'nlm'
"
I don't know why ,can anybody give me some hints ?? thanks in
advance.
regards .
2008 Oct 30
0
a nlm() question
Dear R listers,
I have a very annoying problem using nlm().
I want to find the minimizer of my target function, if written in
\LaTeX is
f(\mu1,\mu2,\sigma1,\sigma2) = \sum_i^n( w_ig_t(z_i) ), where
g_t(z) is a pdf of bivariate normal distribution and z_i is my samples.
I cannot get the estimation result generated by nlm(), and I got
the following errors
"
Error in
2008 Sep 16
5
How to find the index
Dear R experts,
i have a vector z , i have to do something after z is sorted. how
can i find the original index, i.e., before sorting, of a certain
element in the sorted vector .
thanks in advance
regards
-----------------------------------------------
Peng Jiang ?? ,Ph.D. Candidate
Antai College of Economics & Management
????????
Department of Mathematics
???
Shanghai Jiaotong
2008 Jun 30
0
Fwd: cannot install the package RMySQL
Hi,
I first report the installing error to the r-sig-mac mailing list but
it seems
nobody ever encounter this annoying problem and I got no replies. so I
am trying to forward it to this list, hope it never bothers.
Anyone had the same problem, or what does the warning message mean ?
Thank you in advance !
Begin forwarded message:
> From: Peng Jiang <jp021@sjtu.edu.cn>
> Date:
2008 Jun 23
3
Simulating Gaussian Mixture Models
Hi,
Is there any package that I can use to simulate the Gaussian
Mixture Model , which is a mixture modeling method that is widely used
in statistical learning theory.
I know there is a mclust, however, I think it is a little bit
different from my problem.
Thanks very much..
regards.
--------------------------
Peng Jiang
??
Ph.D. Candidate
Antai College of Economics &
2008 Jul 03
2
what can we do when R gives no response
Hi, dear R experts ,
I am new. I met this problem when I am trying to learn how to use
the nlminb() function. I tried the example which the document
provides ( as the following code ) and R gives no response . I don't
know whether it is running or not and it takes a very long time but
still output nothing so I just close the session window. my question
is is there any method
2009 Mar 27
2
how to quit mailing list
Dear list,
I will not use this account later, so i have to quit this list.
I don't know how to quit this list, I search the official website
and find no answer.
thanks very much !!
[[alternative HTML version deleted]]
2008 Jun 30
6
Plotting three time series on the same graph
Dear R Users,
I would like to plot three time series on the same graph, two axis on the
left and one axis on the right.
The time series that I am graphing on the left do not share a similar
scale: one has a range of 1:100 and the other a range of 25000:70000. How
can I display the tick marks for both on the left hand side without
superimposing them, i.e. one set of tick marks in black right
2017 Jun 04
5
[Bug 12817] New: [PATCH] Allow daemon itself to chroot
https://bugzilla.samba.org/show_bug.cgi?id=12817
Bug ID: 12817
Summary: [PATCH] Allow daemon itself to chroot
Product: rsync
Version: 3.1.2
Hardware: All
OS: All
Status: NEW
Severity: normal
Priority: P5
Component: core
Assignee: wayned at samba.org
Reporter:
2006 Mar 07
3
returning the largest element in an array/matrix?
Hi all,
I want to use "which.max" to identify the maximum in a 2D array/matrix and I
want "argmin" and return the row and column indices.
But "which.max" only works for vector...
Is there any convinient way to solve this problem?
Thanks a lot!
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2003 Dec 18
2
: Lp norm estimation
Hi all
Just wondering whether one can undertake Lp norm estimation (a type of
regression analysis) in R?
i.e.
argmin S ( | y(i) - x(i)b | ^p )
where:
* S is the summation over observation i= 1,2,...,n
* y is a vector of n observations
* x is an n by p matrix of explanatory variables
* b is a p by 1 vector of beta coefficients and
* p is a constant to be estimated such that
2007 Aug 01
1
constrOptim
Hi,
I'm having trouble using the constrOptim function to generate the
9-component vector argmin of the function ELfsds:
ELfsds <- function(pvechat){
LG=0
for(i in 1:9){
LG=LG+log(pvechat[i])
}
return(-LG)
}
with accompanying gradient function:
gradfunc <- function(thetavec){
g=1/(9*thetavec)
return(g)
}
The constraints on the optimization problem are:
1 - components of
2009 Jan 05
1
Porting Speex to embedded 32bit
>Dear Speex developers
>I am going to port Speex on LPC2368
>I tested Speex encoding and the mesurments shows ~40ms cpu time for one
>frame
>Do you know who ported speex to NXP or other 32bit platform?
>Best Regards
>Zohar fox
I have an own optimisation for Speex for different versions of ARM architecture.
Here is Measurements of performance for STM32 72 MHz.
4000
2010 Dec 10
3
Adding numbers in Outputs
two OutputsHello!
I am Amelia from Auckland and work for a bank. I am new to R and I have started my venture with R just a couple of weeks back and this is my first mail to R-forum. I need following assistance
Suppose my R code generates following outputs as
> X
[[1]]
[1] 40
[[2]]
[1] 80 160
[[3]]
[1] 160 80 400
> Y
[[1]]
[1] 10
[[2]]
[1] 10 30
[[3]]
[1] 5 18 20
2011 May 02
1
Optimization - n dimension matrix
Dear all,
I am facing the following problem in optimization:
w = (d, o1, ..., op, m1, ..., mq) is a 1 + p + q vector
I want to determine:
w = argmin (a - d(w))' A (a - d(w))
where a is a 1xK marix, A is the covariance matrix of vector a, d(w) is a
1xK vector which parameters are functions of parameters d, o1 .. op, m1 ..
mq.
Is there some function to solve this problem easily? I know
2008 Jul 08
1
about EM algorithm
Hi, dear R experts .
is there any package contain an universal EM procedure,
that is , for arbitrary d.f. , not just the one in mclust .
thanks in advance
best regards
-----------------------------------------------
Peng Jiang ?? ,Ph.D. Candidate
Antai College of Economics & Management
????????
Department of Mathematics
???
Shanghai Jiaotong University (Minhang Campus)
800 Dongchuan Road
2008 May 03
3
Excluding/removing row and column names on text output files
Dear R users,
I've had no joy finding a solution to this online or in any of my R books.
Many thanks in advance for any help you can give.
I'm seeking to output a data frame (or matrix - it doesn't matter which for
my purposes) to a .txt file, but omit any row or column names. The data
frame that I'm using doesn't actually have column or row names to start with
as it has been
2006 Feb 13
5
search algorithm
Hi!
I have a problem of finding a specific value in a column. For example, I
have a matrix with say 2 columns
X Y
1 -2.0341602 9.036689e-05
2 -1.4287230 1.807338e-04
3 -1.1194402 2.711007e-04
4 -1.0327582 3.614676e-04
5 -0.8130556 4.518344e-04
6 -0.7138212 5.422013e-04
7 -0.6634425 6.325682e-04
8 -0.6512083 7.229351e-04
9
2013 Nov 23
1
windows can not see the content of samba shared folder
Hello,
I want to access a shared folder on my linux from a windows machine. The smb.conf has this entry
?? [samba_share]
??????? comment = QEMU share place
??????? path = /media/samba_share
??????? valid users = mahmood vb
??????? public = no
??????? writable = yes
??????? printable = no
??????? create mask = 0777
Then I added a user to samba with "smbpasswd mahmood". The folder mask