Displaying 20 results from an estimated 100000 matches similar to: "normalized kernel question:"
2010 Jul 06
2
numerical derivative R help
I fit my CDF to sum of exponentials and now I want to take the numerical
derivative of this function to obtain probability density.I will really
appreciate your help reagrding the error messages I am getting which I don't
understand.
*
*
> fitterma <- function(xtime) {
a <- -0.09144115
b <- -0.01335756
c <- -2.368057
d <- -0.00600052
2010 Jun 23
1
Probabilities from survfit.coxph:
Hello:
In the example below (or for a censored data) using survfit.coxph, can
anyone point me to a link or a pdf as to how the probabilities appearing in
bold under "summary(pred$surv)" are calculated? Do these represent
acumulative probability distribution in time (not including censored time)?
Thanks very much,
parmee
*fit <- coxph(Surv(futime, fustat) ~ age, data = ovarian)*
2010 Apr 01
1
predicted time length differs from survfit.coxph:
Hello All,
Does anyone know why length(fit1$time) < length(fit2$n) in survfit.coxph
output? Why is the predicted time length is not the same as the number of
samples (n)?
I tried: example(survfit.coxph).
Thanks,
parmee
> fit2$n
[1] 241
> fit2$time
[1] 0 31 32 60 61 152 153 174 273 277 362
365 499 517 518 547
[17] 566 638 700 760 791
2006 Feb 02
0
How do I normalize a PSD?
Dear Tom,
Short answer, if your using spec.pgram(), use the smoothing kernel to get a
better estimate at the frequency centered in the bandwidth. If your
frequency bin of interest is wider than the bandwidth of the kernel, average
across frequencies (I think). The estimate appears to be normalized already.
If you are calculating your PSD independently, then oversample (e.g. 2,
perhaps 4 or more
2009 Aug 19
3
R function for Probabilities for the (standard) normal distribution
Dear All,
I need to write an R function which computes values of Probabilities for
the (standard) normal distribution, ¦µ(z) for z > 0 by summing this power
series. (We should accumulate terms until the sum doesn't change). I also
need to make the function work for vector of values z.
The initial fomular is
¦µ(z) = ( 1/ sqrt(2¦Ð) )* ¡Ò e^(-t^2/2)dt (¡Ò is from -¡Þ, z)
2009 Dec 10
1
incorrect multiple outputs
HI,
I'm having trouble with a piece of Rscript which keeps outputting
incorrectly. it's something like this: the code reads in from a file which
contains (reformated) input
>file<-read.table(file="input_file.txt",sep="\t")[,c(1,3:5)]
>
>file.rows<- c(nrow(file)/288) # "input_file.txt" contains 288 reformatted
lines for each original data file
2016 May 27
2
Channel Mapping Family for Ambisonics
Hello Jean-Marc,
Thanks for the quick reply and comments.
On Thu, May 26, 2016 at 5:41 PM, Jean-Marc Valin <jmvalin at jmvalin.ca> wrote:
> Hi Michael,
>
> Here's some more minor comments below. As long as you address the two
> comments from my previous email (254 -> 2 and the draft name), the draft
> is good for submitting as initial version on the IETF website (even
2010 Feb 23
0
BUG with LSSVM in R:
Hello,
I have noticed a bug with LSSVM implementation in R. It could be a bug with
the LSSVM itself that causes this problem.
I thought I should post this message to see if anyone else is familiar with
this problem and explain why the result is different for odd and even number
of cases.
Once the hyperplane is found using LSSVM, the prediction results vary when
you predict odd or even number of
2009 May 11
0
Partial correlation function required
---------- Forwarded message ----------
From: <r-help-bounces@r-project.org>
Date: Mon, May 11, 2009 at 10:24 PM
Subject: The results of your email commands
To: das.moumita.online@gmail.com
The results of your email command are provided below. Attached is your
original message.
- Results:
Ignoring non-text/plain MIME parts
- Unprocessed:
What is the function for partial
2007 Jul 23
1
code optimization tips
Hi,
Being new to R I'm asking for some advice on how to optimize the
performance of the following piece of code:
> alpha_c <- function(lambda=600e-9,alpha_s=1e-14,N=400,spacing=1e-7){
>
> k<-2*pi/lambda
> ri<-c(0,0) # particle at the origin
> x<-c(-N:N)
> positions <- function(N) {
> reps <- 2*N+1
> matrix(c(rep(-N:N, each = reps), rep(-N:N,
2000 Jul 03
2
Possible bug in psy.c
Hi all,
I'm quite new to Vorbis, so please excuse me if I'm writing complete
nonsense (and, if possible, tell me where I'm wrong).
While searching for optimization possibilities in lib/psy.c, I found the following
piece of code in _vp_compute_mask():
if(p->vi->smoothp){
/* compute power^.5 of three neighboring bins to smooth for peaks
that get split twixt
2012 Nov 22
1
Efficiently creating/defining new variables transformations
I would like to add an extension to the current name of a variable to create
a new variable that is its sqrt transform. Each piece of the equation below
works independently, but the left side definition fails on run. I also tried
creating the variable name first, but ended up with an object that
toString() did not fix. Better ideas?
Example 1
2012 Jun 04
1
simulation of modified bartlett's test
Hi, I run this code to get the power of the test for modified bartlett's
test..but I'm not really sure that my coding is right..
#normal distribution unequal variance
asim<-5000
pv<-rep(NA,asim)
for(i in 1:asim)
{print(i)
set.seed(i)
n1<-20
n2<-20
n3<-20
mu<-0
sd1<-sqrt(25)
sd2<-sqrt(50)
sd3<-sqrt(100)
g1<-rnorm(n1,mu,sd1)
g2<-rnorm(n2,mu,sd2)
2006 May 15
0
reproducing scaling used in biplot(pc.biplot=TRUE)
Hello,
I'd like to reproduce the standard biplot with pc.biplot=TRUE using
xyplot in lattice in order to assign different symbols to groupings
of observations (similar to the example in fig. 11.2 on page 285 in
DAAG). In order to reproduce the biplots I need to know how to scale
the observations and variables. In ?biplot.princomp I found that the
variables are scaled by 'lambda ^
2008 Apr 18
3
help me to debug this part of code?
I am trying to solve the integration equation, for different values of K from
4 to 25, the integration is with respect to u,
Here is the equation: gamma(k/2) / ( sqrt(k-1)*gamma((k-1)/2) ) *
integrate(f= (1+u^2/k-1)^(-k/2), lower=0, upper= sqrt(a^2*k/(k+1-a^2)) ) =
the similar expression as te left hand except k becomes k+1
my code is below, I don't know why R keep telling me the syntax
2008 Feb 19
1
recursive function help
I'm trying to implement a recursive function using integrate, and I
suspect I need a Vectorize somewhere,
but I can't suss it out. Any help would be appreciated. I've tried
traceback() and various debugging ideas to no avail (most likely due to
my inexperience with these tools.)
Here's what I have.
Nk <- function(m, C) {
if (length(m) > 1) {
rho <- C[1, -1]
2006 Jan 31
1
How do I "normalise" a power spectral density
I have done a fair bit of spectral analysis, and hadn't finished collecting my thoughts for a reply, so hadn't replied yet.
What exactly do you mean by normalize?
I have not used the functons periodogram or spectrum, however from the description for periodogram it appears that it returns the spectral density, which is already normalized by frequency, so you don't have to worry about
2003 Jun 09
1
understanding eigen(): getting non-normalized eigenvectors
Hi, dear R pros
I try to understand eigen(). I have seen, that eigen() gives the
eigenvectors normalized to unit length.
What shall I do to get the eigenvectors not normalized to unit length?
E.g. take the example:
A
[,1] [,2]
V1 0.7714286 -0.2571429
V2 -0.4224490 0.1408163
Calculating eigen(A) "by hand" gives the eigenvectors (example from
Backhaus,
2012 Jan 08
0
Adding a migration element to a deterministic spatial model
Hi all,
I've been working with a friend's model that is a spatial model
consisting of 4 patches. She uses the code found below to add
migration between the patches for the three species of concern. When I
run a script incorporating this code, all four patches run
independently without migration occuring. When I type m1[1,2] into the
workspace to see if it will return a figure, it returns,
2004 Dec 28
2
Sound distorted after normalized.
Dear all,
First, my aim is to achieve VoIP using VBR and DTX
under Win32.
I face a problem using speex 1.0.4 and need some help.
My voice is ok and no background noise when I do NOT
normalize 16 bit value to floating value. Normalized
means dividing the 16 bit value by 32767. Turning on
VBR is also ok but DTX has no effect.
However, the speak is has a continous background beep
sound AFTER I