Displaying 20 results from an estimated 500 matches similar to: "problem with Gauss Hermite ( x and w )"
2004 May 28
3
gauss.hermite?
The search at www.r-project.org mentioned a function
"gauss.hermite{rmutil}". However, 'install.packages("rmutil")'
produced, 'No package "rmutil" on CRAN.' How can I find the current
status of "gauss.hermite" and "rmutil"?
Thanks,
Spencer Graves
2006 Feb 27
1
gauss.hermite function
Hi,
I am trying to find a function that returns simply the weights and
points of an n point gauss hermite integeration, so that I can use them
to fit a non-standard likelihood.
I have found some documentation for the function 'gauss.hermite' written
by jim lindley, but can't find the actual binary on CRAN
I'm aware there are lots of functions like glmm, glmmML etc to fit mixed
2012 Mar 23
3
R numerical integration
Hi all,
Is there any other packages to do numerical integration other than the
default 'integrate'?
Basically, I am integrating:
integrate(function(x) dnorm(x,mu,sigma)/(1+exp(-x)),-Inf,Inf)$value
The integration is ok provided sigma is >0.
However, when mu=-1.645074 and sigma=17535.26
It stopped working. On the other hand, Maple gives me a value of
0.5005299403.
It is an
2023 Nov 09
1
Dependency errors for package pracma
I tried to update my package {pracma} on CRAN from 2.4.2 (2022-09-21)
to version 2.4.4 (2023-11-08). This package reverse depends / imports
/ suggests on 350 packages on CRAN and 25 packages on Bioconductor.
The only changes are small corrections on some help files, a new
function for stereographic projection, and `gcd` and `Lcm` require
integer inputs now (these functions are not used in the
2013 Feb 15
1
minimizing a numerical integration
Dear all,
I am a new user to R and I am using pracma and nloptr libraries to minimize
a numerical integration subject to a single constraint . The integrand
itself is somehow a complicated function of x and y that is computed
through several steps. i formulated the integrand in a separate function
called f which is a function of x &y. I want to find the optimal value of x
such that the
2012 Dec 31
2
code to convert 3D geographical coordinates to Cartesian?
Is there packaged code to convert geographical coordinates (e.g.,
longitude, latitude, elevation) to Cartesian coordinates in 3-space?
I can see how to do this using
1. a spherical-to-Cartesian conversion like pracma::sph2cart(tpr)
http://cran.r-project.org/web/packages/pracma/
2. a geographical-to-spherical conversion. This seems to involve (in
roughly increasing order of difficulty or
2012 Jan 27
3
Numerical instability in new R Windows development version
I have a question concerning the new Windows toolchain for R >= 2.14.2.
When trying out my package 'pracma' on the win-builder development version
it will stop with the following error message:
> f3 <- function(x, y) sqrt((1 - (x^2 + y^2)) * (x^2 + y^2 <= 1))
> dblquad(f3, -1, 1, -1, 1) # 2.094395124 , i.e. 2/3*pi , err = 2e-8
Warning in sqrt((1 - (x^2 + y^2)) *
2025 Mar 27
1
Problem with minimization that I failed to understand
?s 19:36 de 27/03/2025, Daniel Lobo escreveu:
> My code is to minimize the objective function
>
> therefore, shouldnt I expect that
>
> StartingValue = c(0.12, 0.04, 0.07, 0.03, 0.06, 0.07, 0.07, 0.04, 0.09,
> 0.08, 0.02, 0.02, 0.03, 0.06, 0.02, 0, 0.07, 0.05, 0.02, 0.02, 0.02)
> Fn(q1$par) < Fn(StartingValue)
> ## FALSE
>
> Below is the corrected code that can
2007 May 08
1
Piecewise cubic Hermite interpolation
Which function implements the piecewise cubic Hermite interpolation?
I am looking for equivalent of matlab's interp1 with the method = 'pchip'
Here is the reference
http://www.mathworks.com/access/helpdesk/help/techdoc/index.html?/access/helpdesk/help/techdoc/ref/interp1.html&
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2006 Dec 11
1
hermite and Bezier splines
Does anyone know how to do hermite or
Bezier splines in R? I can find Matlab routines, but really need to
implement them in R. Failing that I'd be interested in other
conformal splines. I need to smooth and interpolate animal tracking data.
Antarctic Wildlife Research Unit
School of Zoology
University of Tasmania
PO Box 252-05
Hobart
TAS, 7001
Australia
Phone: (0)3 6226 2645
Fax:
2023 Aug 13
4
Noisy objective functions
While working on 'random walk' applications, I got interested in
optimizing noisy objective functions. As an (artificial) example, the
following is the Rosenbrock function, where Gaussian noise of standard
deviation `sd = 0.01` is added to the function value.
fn <- function(x)
(1+rnorm(1, sd=0.01)) * adagio::fnRosenbrock(x)
To smooth out the noise, define another
2025 Mar 27
1
Problem with minimization that I failed to understand
My code is to minimize the objective function
therefore, shouldnt I expect that
StartingValue = c(0.12, 0.04, 0.07, 0.03, 0.06, 0.07, 0.07, 0.04, 0.09,
0.08, 0.02, 0.02, 0.03, 0.06, 0.02, 0, 0.07, 0.05, 0.02, 0.02, 0.02)
Fn(q1$par) < Fn(StartingValue)
## FALSE
Below is the corrected code that can be reproduced:
MyDat = structure(list(c(50L, 0L, 0L, 50L, 75L, 100L, 50L, 0L, 50L, 0L,
25L,
2013 Feb 18
2
error: Error in if (is.na(f0$objective)) { : argument is of length zero
Dear all,
I tried running the following syntax but it keeps running for about 4 hours
and then i got the following errors:
Error in if (is.na(f0$objective)) { : argument is of length zero
In addition: Warning message:
In is.na(f0$objective) :
is.na() applied to non-(list or vector) of type 'NULL'
Here is the syntax itself:
library('nloptr')
library('pracma')
#
2025 Mar 27
1
Problem with minimization that I failed to understand
?s 18:35 de 27/03/2025, Daniel Lobo escreveu:
> Hi,
>
> I have below minimization problem
>
>
> MyDat = structure(list(c(50L, 0L, 0L, 50L, 75L, 100L, 50L, 0L, 50L, 0L,
> 25L, 50L, 50L, 75L, 75L, 75L, 0L, 75L, 75L, 75L, 0L, 25L, 75L,
> 75L, 0L, 75L, 100L, 0L, 25L, 100L), c(75L, 0L, 0L, 50L, 100L,
> 50L, 75L, 75L, 100L, 25L, 0L, 25L, 100L, 0L, 50L, 0L, 25L, 25L,
>
2025 Mar 27
2
Problem with minimization that I failed to understand
Hi,
I have below minimization problem
MyDat = structure(list(c(50L, 0L, 0L, 50L, 75L, 100L, 50L, 0L, 50L, 0L,
25L, 50L, 50L, 75L, 75L, 75L, 0L, 75L, 75L, 75L, 0L, 25L, 75L,
75L, 0L, 75L, 100L, 0L, 25L, 100L), c(75L, 0L, 0L, 50L, 100L,
50L, 75L, 75L, 100L, 25L, 0L, 25L, 100L, 0L, 50L, 0L, 25L, 25L,
100L, 75L, 0L, 0L, 0L, 50L, 0L, 75L, 75L, 0L, 50L, 25L), c(50L,
0L, 0L, 0L, 100L, 25L, 0L, 0L,
2012 May 16
3
triangular matrices input/output
Hi,
Is there any package that deals with triangular matrices?
Say ways of inputting an upper (lower) triangular matrix?
Or convert a vector of length 6 to an upper (lower) triangular matrix (by
row/column)?
Thanks!
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2010 Nov 14
1
Integrate to 1? (gauss.quad)
Does anyone see why my code does not integrate to 1?
library(statmod)
mu <- 0
s <- 1
Q <- 5
qq <- gauss.quad(Q, kind='hermite')
sum((1/(s*sqrt(2*pi))) * exp(-((qq$nodes-mu)^2/(2*s^2))) * qq$weights)
### This does what's it is supposed to
myNorm <- function(theta) (1/(s*sqrt(2*pi))) * exp(-((theta-mu)^2/(2*s^2)))
integrate(myNorm, -Inf, Inf)
2025 Mar 28
1
Problem with minimization that I failed to understand
I haven't run your code, but since Kendall correlation is based on
ranks, your Fn is probably locally constant with jumps when the ranks
change. That's a really hard kind of function to maximize, and the
algorithm used by fmincon is not appropriate to do it.
Sorry, but I don't know if there is an R function that can do
constrained discrete maximization.
Duncan Murdoch
On
2013 Jul 17
2
Using RasterBricks
Dear listers,
I am trying to create a RasterLayer of the values of a rasterbrick object.
The rasterbrick object has, for example, 100cells
library(raster)
r <- raster(ncol=10, nrow=10)
r[]=1:ncell(r)
s <- brick(r,r,r)
s <- s * 1:3
Each cell of the rasterfinal will have the AREA UNDER CURVE formed by the
values in each cell of the three original rasters.
For example:
s[4] has the
2006 May 05
0
Spline integration & Gaussian quadrature (was: gauss.quad.prob)
Spencer
Thanks for your thoughts on this. I did a bit of work and did end up
with a method (more a trick), but it did work. I am certain there are
better ways to do this, but here is how I resolved the issue.
The integral I need to evaluate is
\begin{equation}
\frac{\int_c^{\infty} p(x|\theta)f(\theta)d\theta}
{\int_{-\infty}^{\infty} p(x|\theta)f(\theta)d\theta}
\end{equation}
Where