Displaying 12 results from an estimated 12 matches for "d_i".
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2009 Apr 21
2
Changing the binning of collected data
Dear All,
Apologies if this is too simple for this list.
Let us assume that you have an instrument measuring particle distributions.
The output is a set of counts {n_i} corresponding to a set of average
sizes {d_i}.
The set of {d_i} ranges from d_i_min to d_i_max either linearly of
logarithmically.
There is no access to further detailed information about the
distribution of the measured sizes, but at least you know enough to
plot n(d_i) (number of counts as a function of particle size).
If you can fit the {n...
2009 Aug 06
1
solving system of equations involving non-linearities
Hi,
I would appreciate if someone could help me on track with this problem.
I want to compute some parameters from a system of equations given a number of sample observations. The system looks like this:
sum_i( A+b_i>0 & A+b_i>C+d_i) = x
sum_i( C+d_i>0 & C+d_i>A+b_i) = y
sum_i( exp(E+f_i) * ( A+b_i>0 & A+b_i>C+d_i) = z
A, C, E are free variables while the other letters represent values given from sample observations. The equations involve counts of the number of fulfilled conditions and therefore non-linea...
2009 Apr 03
1
Hello! I got error in C - R
Hello,
My name is Ick Hoon Jin and I am Ph. D. student in Texas A & M Univ..
When I run the C embedded in R in the Linux system, I confront the
following error after 6,000 iteration. By googling I found this error is
from the problem in C.
*** caught segfault ***
address (nil), cause 'memory not mapped'
My C code is following:
2000 Aug 22
0
Using RNG from MS [forwarded message from Xiaoqiang Li]
This had a VERY WRONG `To:' address and went straight into my
"spam box" into which I don't look too often ..
Martin
------- start of forwarded message -------
Message-ID: <Pine.A41.4.05.10008212237300.18590-100000 at fisher.stats.uwo.ca>
MIME-Version: 1.0
From: Xiaoqiang Li <lxq at stats.uwo.ca>
To: Majordomo-Owner at stat.math.ethz.ch
Subject: r-help
Date: Mon,
2017 Nov 09
2
R-help
Generate a clustered pattern in [0; 1]2 as follows:
(a) Generate nc, say 20, independent cluster centres (which can be called
parents) that are distributed i.i.d. uniformly in the unit square;
(b) then n daughters are assigned i.i.d. uniformly to these parents and
such that each daughter is located i.i.d. uniformly in a disk of radius r =
0:1 centred at her parent, under the periodic boundary
2008 Nov 12
1
Understanding glm family documentation: dev.resids
Hi all
Consider the family function, as used by glm. The help page says the value of the family object is a list, one element of which is the following:
dev.resids function giving the deviance residuals as a function of (y, mu, wt).
But reading any of the family functions (eg poisson) shows that dev.resids is a function that computes the *square* of the deviance residuals (at least, by
2008 Jul 31
1
clustering and data-mining...
Hi all,
I am doing some experiment studies...
It seems to me that with different combination of 5 parameters, the end
results ultimately converged to two scalars. That's to say, some
combinations of the 5 parameters lead to one end result and some other
combinations of the 5 parameters lead to the other end result (scalar).
I am thinking of this is sort of something like clustering or
2017 Nov 09
0
R-help
Hi
it smells like a homework, this list has no homework policy.
Anyway, maybe the sample approach could be used.
Generate x,y coordinates - ?expand.grid
sample n centers - ?sample
select all points within defined area - ?point.in.polygon, package sp
select desired number of points - ?sample
Cheers
Petr
> -----Original Message-----
> From: R-help [mailto:r-help-bounces at r-project.org]
2007 Apr 15
1
Use estimated non-parametric model for sensitivity analysis
Dear all,
I fitted a non-parametric model using GAM function in R. i.e.,
gam(y~s(x1)+s(x2)) #where s() is the smooth function
Then I obtained the coefficients(a and b) for the non-parametric terms. i.e.,
y=a*s(x1)+b*s(x2)
Now if I want to use this estimated model to do optimization or sensitivity analysis, I am not sure how to incorporate the smooth function since s() may not
2008 Oct 07
0
splinefun gives incorrect derivs when extrapolating to the (PR#13139)
...z$e <- NULL
function(x, deriv = 0) {
deriv <- as.integer(deriv)
@@ -114,18 +113,25 @@
## where dx := (u[j]-x[i]); i such that x[i] <= u[j] <= x[i+1},
## u[j]:= xout[j] (unless sometimes for periodic spl.)
## and d_i := d[i] unless for natural splines at left
- .C("spline_eval",
- z$method,
- as.integer(length(x)),
- x=as.double(x),
- y=double(length(x)),
- z$n,
- z$x,
- z$y,
- z$b,
- z$c,
- z$d,
- PACKAGE="stats")$y
+ res <- .C("spline_eval",
+...
2008 Oct 07
0
splinefun gives incorrect derivs when extrapolating to the (PR#13138)
...z$e <- NULL
function(x, deriv = 0) {
deriv <- as.integer(deriv)
@@ -114,18 +113,31 @@
## where dx := (u[j]-x[i]); i such that x[i] <= u[j] <= x[i+1},
## u[j]:= xout[j] (unless sometimes for periodic spl.)
## and d_i := d[i] unless for natural splines at left
- .C("spline_eval",
- z$method,
- as.integer(length(x)),
- x=as.double(x),
- y=double(length(x)),
- z$n,
- z$x,
- z$y,
- z$b,
- z$c,
- z$d,
- PACKAGE="stats")$y
+ res <- .C("spline_eval",
+...
2005 Sep 13
4
plot(<lm>): new behavior in R-2.2.0 alpha
...AOV"
situation, something probably pretty rare nowadays in real
practice, but common of course in teaching ANOVA.
As you may remember, in a balanced design, all observations have
the same leverages h_{ii}, and the plot R_i vs h_ii is really
not so useful. In that case, the cook distances CD_i = c * R_i ^2
and so CD_i vs i {the old "4-th plot in plot.lm"} is
graphically identical to R_i^2 vs i.
Now in that case (of identical h_ii's), I think one would really
want "R_i vs i".
Question to the interested parties:
Should there be an automatism
``when h_...