Displaying 20 results from an estimated 100 matches similar to: "Dependency errors for package pracma"
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
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
2012 May 09
2
problem with Gauss Hermite ( x and w )
Hi all,
I am using the 'gaussHermite' function from the 'pracma' library
############ CODES ###########
library(pracma)
cc=gaussHermite(10)
cc$x^2
cc$x^5
cc$x^4
############ CODES ###########
as far so good. However, it does NOT work for any NON integer values, say
############ CODES ###########
cc$x^(2.5)
cc$x^(-2.5)
############ CODES ###########
But just think about it
2012 Jan 27
3
Numerical instability in new R Windows development version
I have a question concerning the new Windows toolchain for R >= 2.14.2.
When trying out my package 'pracma' on the win-builder development version
it will stop with the following error message:
> f3 <- function(x, y) sqrt((1 - (x^2 + y^2)) * (x^2 + y^2 <= 1))
> dblquad(f3, -1, 1, -1, 1) # 2.094395124 , i.e. 2/3*pi , err = 2e-8
Warning in sqrt((1 - (x^2 + y^2)) *
2023 Nov 09
1
Dependency errors for package pracma
What really interests me:
With all those strict checking procedures, how is it possible that the
new 'Matrix' version got accepted on CRAN?
I think this happened twice to me before, and it takes a lot of time
to check package dependencies that turn out to be not dependent --
more time than checking dependencies that are real.
2023 Aug 13
4
Noisy objective functions
While working on 'random walk' applications, I got interested in
optimizing noisy objective functions. As an (artificial) example, the
following is the Rosenbrock function, where Gaussian noise of standard
deviation `sd = 0.01` is added to the function value.
fn <- function(x)
(1+rnorm(1, sd=0.01)) * adagio::fnRosenbrock(x)
To smooth out the noise, define another
2013 Feb 18
2
error: Error in if (is.na(f0$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')
#
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
2024 Feb 24
1
Clustering Functions used by Reverse-Dependencies
Dear R Users,
Are there any tools to extract the function names called by reverse-dependencies?
I would like to group these functions using clustering methods based on the co-occurrence in the reverse-dependencies.
Utility: It may be possible to split complex packages into modules with fewer reverse-dependencies.
Package pkgdepR may offer some of the functionality; but I did not have time to
2012 Apr 02
2
Error in gamma(delta + (complex(0, 0, 1) * (x - mu))/alpha) : unimplemented complex function
I am trying to obtain the grafic of a pdf . but this error keeps showing .
Here is the code
MXN.fd = function(x,alpha,beta,mu,delta)
{
A = (2*cos(beta/2))^(2*delta)
B = 2*alpha*pi*gamma(2*delta)
C = (beta*(x-mu))/alpha
D = abs(gamma(delta + (complex(0,0,1)*(x-mu))/alpha)^2)
M = A/B*exp(C)*D
M
plot(x,M,type="l",lwd=2,col="red")
}
alpha = 0.02612297
beta = -0.50801886
mu =
2011 Nov 10
2
performance of adaptIntegrate vs. integrate
Dear list,
[cross-posting from Stack Overflow where this question has remained
unanswered for two weeks]
I'd like to perform a numerical integration in one dimension,
I = int_a^b f(x) dx
where the integrand f: x in IR -> f(x) in IR^p is vector-valued.
integrate() only allows scalar integrands, thus I would need to call
it many (p=200 typically) times, which sounds suboptimal. The
2011 Nov 22
5
x, y for point of intersection
Hi everyone,
?
I am trying to get a point of intersection between a
polyline and a straight line ?.. and get the x and y coordinates of this point.
For exemplification consider this:
?
?
set.seed(123)
?
k1 <-rnorm(100, mean=1.77, sd=3.33)
?k1 <- sort(k1)
q1 <- rnorm(100, mean=2.37, sd=0.74)
q1 <- sort(q1, decreasing = TRUE)
plot(k1, q1, xlim <- c((min(k1)-5),
2013 Feb 27
0
A program running for a too long time
Dear all,
The attached code is supposed to minimize a numerical integration subject
to a non linear constraint. The code runs for 2 days& more without giving
an output. Also, when i change the value of "m<-100" to "m<-1" it gives an
output in areasonable period but with a message " maximum number of
iterations in romberg has been reached". I need to :
1-
2012 Apr 18
0
Numerical integration again
Hi all,
Here is an integration function
require(pracma) # for 'quadinf'
myint=function(j) {
quadinf(function(x)
(1/(1+exp(-x)))^j*(1-1/(1+exp(-x)))^(k-j)*dnorm(x,mu,casigma),-Inf,Inf)
}
in any optimization routine. It works fine most of the time but failed with
some particular sets of values, say one of the following:
k=20
mu=-1.978295
casigma=0.008326927
>
2011 Nov 03
1
Question about Calculation of Cross Product
The function of crossprod in R puzzled me.
I would like to calculate the cross product of two vectors. According to my text book, it defines like this:
a = (ax, ay, az)
b = (bx, by, bz)
then, the cross product of a and b is:
a X b = (ay*bz-az*by, az*bx-ax*bz, ax*by-ay*bz)
It can also write in a determinant format.
But the crossprod or tcrossprod function in R appeared not calculate the cross
2012 Jan 07
1
k-means++
Hi everyone -
I know that R is capable of clustering using the k-means algorithm, but can
R do k-means++ clustering as well?
Thanks,
--
Dr. Ferebee Tunno
Assistant Professor
Department of Mathematics and Statistics
Arkansas State University
P.O. Box 70
State University, AR. 72467
ftunno@astate.edu
(870) 329-7710
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2013 Feb 16
3
two dimensional integration
Dear R-users,
I'm wondering how to calculate this double integral in R:
int_a^b int_c^y g(x, y) dx dy
where g(x,y) = exp(- alpha (y - x)) * b
Thanks for answering!
Cheers,
Alui
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2011 Dec 31
4
Base function for flipping matrices
Hi all,
Are there base functions that do the equivalent of this?
fliptb <- function(x) x[nrow(x):1, ]
fliplr <- function(x) x[, nrow(x):1]
Obviously not hard to implement (although it needs some more checks),
just wondering if it had already been implemented.
Hadley
--
Assistant Professor / Dobelman Family Junior Chair
Department of Statistics / Rice University
http://had.co.nz/
2012 Feb 29
3
Does anyone knows a KMeans ++ package for R?
Dear all.
I am searching for KMeans ++ for R. I cannot find it.
Do you know any package with it?
Best regards,
Rui