Displaying 20 results from an estimated 100 matches similar to: "Simplex function in R"
2012 Mar 21
1
How to do 2SLS in R
Hi List
I want to carry out structural mode. Following Example l have taken from
Basic Econometrics- Damodar Gujarati :
Advertising intensity function:
Ad/S = a0 + a1M + a2 (CD/S) + a3C + a4C2 + a5Gr + a6Dur – (1)
Concentration function:
C = b0 + b1 (Ad/S) + b2 (MES/S) -(2)
Price-cost margin function:
M = c0 + c1(K/S) + c2Gr + c3C + c4GD + c5(Ad/S) + c6 (MES/S)
2004 Jul 07
3
KalmanSmooth problem
Hello,
In R I am trying to use Kalman filtering to find a solution for an hydrological problem. With Kalman Filtering I want to estimate the discharge comming from three storage bassins. I have programmed a function in R which can run KalmanSmooth. When I'm asking for the function and putting in values, R detects the following error: "Error in as.vector(data) : Argument "S1" is
2007 Jul 31
1
A complicated 'aggregate'
Hi,
I have a financial (zoo) time series with prices and volumes (although I can
get the coredata as a matrix). Due to the data-source some indices have
multiple observations. I want to aggregate these according to a weighted
average.
11:00:01 34 1000
11:00:01 35 500
11:00:01 35 1000
11:00:02 34 500
11:00:02 35 500
should become
11:00:01 34.6 2500
11:00:02 34.5 1000
I currently do this
2007 Aug 02
1
Using 'diff' on zoo vs zooreg classes (possible bug?)
Hello,
Can anyone explain the following behaviour? To me it seems a bug, but maybe
it is intentional.
It seems that a diff on a zooreg class that is not _strictly_ regular only
considers those entries that are 'deltat' apart.
In the following, diff on the zooreg class only returns values where the
index was one second apart. The example replicates by dev code, but I've
also tested
2007 Jul 31
1
POSIXct Formating Error (PR#9819)
To Whom It May Concern:
The following appears to be a bug in the way POSIXct dates are formated.
The example is forced, but occurs naturally when importing Excel type dates
(where fractional part is fraction of a day) and small rounding errors
result.
As shown, looking at the POSIXct class, it looks as if both times are
16:11:03 (truncation)
Looking at as.numeric.POSIXct, it looks as if
2010 Apr 28
1
Problem with optimization (constrOptim)
Hello,
I have the following problem:
I have a set of n matrix equations in the form of :
[b1] = [A] * [b0]
[b2] = [A] * [b1]
etc.
vertical vectors [b0], [b1], ... are GIVEN. We try to estimate matrix A. As
there are many equations (more than cells in matrix A) the system has no
solutions.
A is transition matrix (stochastic matrix) or markov process, so the sum of
each row = 1 and each entry is
2012 Sep 23
3
Confused by code?
x<-matrix(c(1,0,0,0,1,0,0,0,1),nrow=3)
> y<-matrix(c(0,0,0,1,0,0,1,1,0),nrow=3)
> z<-matrix(c(0,1,0,0,1,0,1,0,0),nrow=3)
> x[z]<-y[z]
The resultant matrix x is all zeros except for the last two diagonal cells
which are 1's.
While y is lower triangualr 0's with the remaining cells all ones.
I really don't understand how this deceptively simple looking piece of
2009 Dec 08
1
Simplex Density Plots
Hello,
I have just started using R, and have found it quite easy to make
plots of probability densities for normal and beta distributions, etc.
Now, I'm looking at trying to make a simplex plot of a Dirichlet
density, but have gotten stuck and was hoping that someone could help.
Ideally, the plot would look something like the 3d plots on Wikipedia here:
2003 Apr 02
1
n.iter in simplex()
Dear R users,
Is anyone familiar with the "n.iter" argument of the simplex() function
(in the boot package)? It seems it doesn't have an effect no matter what
value I set it ...
I'm trying to solve a linear programming problem and running into the
problem of
simplex.object$solved = 0
or
"A value of 0 indicates that the maximum number of iterations was reached
without
2002 Nov 22
1
simplex problem (PR#2317)
Full_Name: George F. LeCompte
Version: 1.6.1
OS: Windows 98
Submission from: (NULL) (208.8.162.161)
This may be a newbie problem. I am attempting tor unt the simplex routine from
the boot package. The example code doesn't find simplex. What's wrong here?
> help(simplex,package=boot)
> # from the resulting article
>
> # This example is taken from Exercise 7.5 of
2002 Jan 25
0
Simplex difficulties
I'm exploring the simplex algorithm with a simple transportation problem
of the form:
minimize:
8a + 6b + 10c + 9d + 5e + 7f
subject to the constraints:
a + b + c = 11
d + e + f = 14
a + d = 10
b + e = 8
c + f = 7
I've implemented this in R (1.4.0 (2001-12-19), SunOS 5.7) as:
require(boot)
costs = c(8,6,10,9,5,7)
constraints = c(
1,1,1,0,0,0,
0,0,0,1,1,1,
1,0,0,1,0,0,
2003 Oct 11
1
Simplex "Out of Bounds" Error
I am running the following code (testing the use of the simplex function to
determine if a point is in the convex hull of another set of points or not):
>a <- c(0, 0)
>A3 <-matrix(c(1,2,3,4,1,1), ncol = 2, byrow = T)
>b3 <-c(1.5, 3.5, 1)
>simplex(a = a, A3 = A3, b3 = b3)
and the following error message appears:
Error in simplex1(out1$a[1:(n + m1 + m2)], out1$A[, 1:(n + m1
2005 Mar 11
1
Simplex(boot) returning invalid answer
In trying to use simplex() from the boot package, I have run into a
situation that doesn't seem like it should be possible. It is claiming
that it has solved the LP, but returns a vector of all zeros, which
does not satisfy the constraints I passed in. A small example:
> ubMatrix <- matrix(c(1,1,-1,0,-1,-1), 3, 2)
> ubVector <- c(2,1,-1)
> objective <- c(0,1)
>
2007 Nov 30
1
simplex projection and S-Map
I am interested in using the nonlinear forecasting techniques developed
by Sugihara et al. In particular the simplex projection and the S-Map
(see this website for details and reprints: http://iod.ucsd.edu/simplex/ ).
I've looked through CRAN but could not find any package with functions
that allow such analysis.
Any pointers?
Thanks,
Manu
2010 Oct 23
1
contour on a simplex
Hello,
anyone knows if there is a way in R to draw contour on a simplex based on a
function f(x,y,z) with domain (x+y+z = 1)?
Thank you!
gigi
[[alternative HTML version deleted]]
2009 Jun 19
2
Manipulate solution of simplex
Hi,
I need some help. I'm doing a project that demands me to obtain several
simplex solutions and I would like to can keep the solution in a vector or
something to be able to use it after I get it.
The comand simplex() prints the solution but how can I keep it?
Another alternative would be to export it to excel, how can I do this?
I just see the solution and have to note it on a paper or
2009 Oct 10
2
Nelder-Mead with output of simplex vertices
Greetings!
I want to follow the evolution of a Nelder-Mead function
minimisation (a function of 2 variables). Hence each simplex
will have 3 vertices.
Therefore I would like to have a function which can output
the coordinates of the 3 vertices after each new simplex
is generated. However, there seems to be no way (which I can
detect) of extracting this information from optim() (the
2002 Sep 25
1
rbind(NULL,NULL) and simplex()
Hello everybody.
I found out the other day something quite astonishing (which I guess
is not astonishing at all to those in the know): in d-dimensional
space, determining whether a given point is inside the convex hull of
a set of n points is elegantly and quickly solvable using linear
programming.
If the columns of matrix "ff" are the coordinates of the set of
points, then in d=2
2007 Jul 10
2
integration over a simplex
Hello
The excellent adapt package integrates over multi-dimensional
hypercubes.
I want to integrate over a multidimensional simplex. Has anyone
implemented such a thing in R?
I can transform an n-simplex to a hyperrectangle
but the Jacobian is a rapidly-varying (and very lopsided)
function and this is making adapt() slow.
[
A \dfn{simplex} is an n-dimensional analogue of a triangle or
2009 May 30
2
Simplex voice on TDM410P
Hello,
I am working on a trixbox based system with a TDM410P connected to 3
phone lines from the CO. The asterisk box is on a full duplex 100Mb LAN
with some polycom and Aastra SIP phones. In general everything works.
the problem I am trying to solve is that if both parties to a call speak
at the same time one of the voices gets cut out such that the talker A
cannot hear what talker B is