Displaying 20 results from an estimated 58 matches for "amat".
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2005 Jan 13
1
how to use solve.QP
...bLo=0 <= w <= 1=bUp
Cov <- var(S)
mu <- apply(S, 2, mean)
mu.target <- 0.1
#subject to cLo <= A <= cUp and bLo=0 <= b <= 1=bUp
A <- rbind(1,mu)
cLo <- c(1, mu.target)
cUp <- c(1, Inf)
bLo <- rep(0, n)
bUp <- rep(1, n)
#I convert [cLo <= A <= cUp] to Amat >= bvec and [bLo=0 <= w #<=1=bUp] to
Amat <- rbind(-1, 1, -mu, mu)
dim(bLo) <- c(n,1)
dim(bUp) <- c(n,1)
bvec <- rbind(-1, 1, mu.target, Inf, bLo, -bUp)
zMat <- matrix(rep(0,2*n*n),ncol=n, nrow=n*2)
zMat[,1] <- c(rep(1,n), rep(-1,n))
Amat <- t(rbind(Amat, zMat))
#So I...
2007 Sep 03
2
The quadprog package
...g)
Dmat<-diag(1,7,7)
# muss als quadratische Matrix eingegeben werden
Dmat
dvec<-matrix(0,7,1) # muss als Spaltenvektor eingegeben werden
dvec
mu<-0 # (in Mio. €)
bvec<-c(1,mu,matrix(0,7,1)) # muss als Spaltenvektor eingegeben werden
bvec
mu_r<-c(19.7,33.0,0.0,49.7, 82.5, 39.0,11.8)
Amat<-matrix(c(matrix(1,1,7),7*mu_r,diag(1,7,7)),9,7,byrow=T)
# muss als Matrix angegeben werden, wie sie wirklich ist
Amat
meq<-2
loesung<-solve.QP(Dmat,dvec,Amat=t(Amat),bvec=bvec,meq=2)
loesung
# Überprüfen, ob System richtig gelöst wurde
loesung$solution %*% mu_r
sum(loesung$solution)
for...
2008 Aug 05
1
Fix for nls bug???
...g nls. I think it may be a restriction in the
applicability of nls and I may have found a fix, but I've been wrong before.
This example is simplified to the essentials. My real application is much
more complicated.
Take a function of matrix 'x' with additional arguments:
matrix 'aMat' whose values are _not_ to be determined by nls
vector 'Coeffs' whose vales _are_ to be determined.
For simplicity, this isn't a selfStart function with an 'initial' attribute,
but that doesn't change things.
Myfunc<-function(x, aMat, Coeffs)
{
#
# result = quadrati...
2009 Feb 16
2
solve.QP with box and equality constraints
...l periods from aggregate data using restricted least
squares.
I seem to be making headway using solve.QP(quadprog) as the unrestricted
solution matches the example I am following, and I can specify simple
equality and inequality constraints. However, I cannot correctly specify a
constraint matrix (Amat) with box constraints per cell and equality
constraints that span multiple cells. Namely the solution matrix I am aiming
for needs to respect the following conditions:
- each row must sum to 1
- each cell must >= 0
- each cell must <= 1
I understand the general principle of creating bo...
2003 Jun 02
1
Help with factorized argument in solve.QP
...en factorized=TRUE, the Dmat argument should
be a matrix R^(-1), such that the Hessian of the objective function is
t(R) %*% R.
I modified the example in the helpfile slightly to test this out:
R = matrix(rnorm(9),3,3)
R.inv = solve(R)
Dmat = t(R) %*% R
dvec = c(0,5,0)
Amat = matrix(c(-4,-3,0,2,1,0,0,-2,1),3,3)
bvec = c(-8,2,0)
x1 = solve.QP(Dmat=Dmat, dvec=dvec, Amat=Amat, bvec=bvec,
factorized=FALSE)
x2 = solve.QP(Dmat=R.inv, dvec=dvec, Amat=Amat, bvec=bvec,
factorized=TRUE)
print(x1$solution)
print(x2$solution)
I would have expected that...
2011 May 11
1
Problem with constrained optimization with maxBFGS
...ar all,
I need to maximize the v:
v= D' W D
D is a column vector ( n , 1)
W is a given matrix (n, n)
subject to:
sum D= 1
(BTW, n is less than 300)
I´ve tried to use maxBFGS, as follows:
#####################################
objectiveFunction<-function(x)
{
return(t(D)%*%W%*%D)
}
Amat<-diag(nrow(D))
Amat<-rbind((rep(-1, nrow(D))), Amat)
bvec<-matrix( c(0), nrow(D)+1, 1)
bvec[1,1]<-c(1)
startValues=rep(1/nrow(D),nrow(D)) #Istart value is homogeneous distribution
res <<- maxBFGS(objectiveFunction, start=startValues,
constraints=list(ineqA=Amat, ineqB=bvec))
#####...
2006 Jun 06
1
Problems using quadprog for solving quadratic programming problem
...I would be very happy, if anyone could help and tell me, where's my mistake. Thank you very much. Fabian
My R-code also containing the sampel of quadprog starts here:
#sample from quadprog package
library(quadprog)
Dmat <- matrix(0,3,3)
diag(Dmat) <- 1
dvec <- c(0,5,0)
Amat <- matrix(c(-4,-3,0,2,1,0,0,-2,1),3,3)
bvec <- c(-8,2,0)
erg<-solve.QP(Dmat,dvec,Amat,bvec=bvec)
print(erg)
erg<-erg$solution
-dvec%*%erg+.5*erg^T%*%Dmat%*%erg
# my "non working" sample
n<-2
k<-2
Dmatj<-diag((n-1),n)
Dmatj[lower.tri(Dmatj)]<--2
Dm...
2005 Nov 29
1
Constraints in Quadprog
...9;m having difficulty figuring out how to implement the
following set of constraints in Quadprog:
1). x1+x2+x3+x4=a1
2). x1+x2+x5+x6=a2
3). x1+x3+x5+x7=a3
4). x1+x2=b1
5). x1+x3=b2
6). x1+x5=b3
for the problem: MIN (x1-c1)2+(x2-c2)2+...+(x8-c8)2.
As far a I understand, "solve.QP(Dmat, dvec, Amat, bvec, meq=0,
factorized=FALSE)" reads contraints using an element-by-element
multiplication, i.e. Amat'*x, not using the matrix-product, i.e.
Amat'%*%x, required for the sums on the left-hand-side of 1-6).
I would very much appreciate a suggestion on this problem.
Thank you,
Sergue...
2008 Mar 03
2
Constrained regression
Dear list members,
I am trying to get information on how to fit a linear regression with
constrained parameters. Specifically, I have 8 predictors , their
coeffiecients should all be non-negative and add up to 1. I understand it is
a quadratic programming problem but I have no experience in the subject. I
searched the archives but the results were inconclusive.
Could someone provide suggestions
2013 Mar 15
1
quadprog issues---how to define the constriants
...question:
w = arg min 0.5*w'Mw - w'N
s. t. sum(w) = 1;
w>0
note: w is weight vector, each w_i must >=0, and the sum of w =1.
Here is my R code:
A <-matrix(c(2.26,1.26,1.12,1.12,2.27,1.13,1.12,1.13,2.2),3,3);
B <- c(0.007459281,0.007448885,0.007447850);
M <-nrow(A);
Amat <- cbind(rep(1,M), diag(M));
bvec <- c(1,rep(0,M)) ;
meq <- 1;
min <- solve.QP(Dmat=A,dvec=B,Amat=Amat,bvec=bvec,meq=meq)
init_prior.weig <-min$solution;
cat("weight = ",init_prior.weig,"\n" )
My question is: When I tried "big"...
2006 Mar 18
1
listing nodes in paths
Hi All,
I have the following adjacency matrix for a directed graph:
[,1] [,2] [,3] [,4] [,5] [,6] [,7] [,8]
[1,] 0 0 0 0 0 0 0 0
[2,] 0 0 0 0 0 0 0 0
[3,] 1 0 0 0 0 0 0 0
[4,] 0 0 1 0 0 0 0 0
[5,] 0 0 1 0 0 0 0 0
[6,] 1 1 0 0 0 0 0 0
[7,] 0 0
2007 Dec 22
1
using solve.qp without a quadratic term
...QP that I am unaware of ? Thanks for any suggestions.
# IN THE CODE BELOW, WE MINIMIZE
# -3*b1 + 4*b2 + 6*b3
# SUBJECT TO
# b1 + b2 + b3 >=0
# -(b1 b2 + b3) >= 0
# IE : b1 + b2 + b3 = 0.
Dmat <- matrix(0,3,3) # QUADRATIC TERM
dvec <- c(-3,4,6) # LINEAR TERM
Amat <- matrix(c(1,-1,0,1,-1,0,1,-1,0),3,3)
#print(Amat)
bvec = c(0,0,0) # THIRD ZERO IS SAME AS NO CONSTRAINT
result <- solve.QP(Dmat, dvec, Amat)
2010 Feb 19
1
Quadprog help
...jective function, I
assume that I have to enter them as zero's in the vector "dvec" and the
matrix "Dmat".
My program states as:
mat<-matrix(0,15,15)
diag(Dmat)<-c(10,5,8,10,20,10,0,0,0,0,0,0,0,0,0)
dvec<- c(-200,-100,-160,-50,-50,-50,0,0,0,0,0,0,0,0,0)
Amat<- matrix(c(-1,0,0,1,0,0,0,0,0,0,0,0,0,0,0,0,-1,0,1,
0,0,0,0,0,0,0,0,0,0,0,0,0,-1,1,0,0,0,0,
0,0,0,0,0,0,0,-1,0,0,0,1,0,0,0,0,0,0,0,
0,0,0,0,-1,0,0,1,0,0,0,0,0,0,0,0,0,0,0,
0,-1,0,1,0,0,0,0,0,0,0,0,0,0,-1,0,0,0,0,...
2012 Mar 16
1
quadprog error?
...act Berwin A. Turlach <Berwin.Turlach at gmail.com>
(maintainer for quadprog package) a week ago, with no success.
##############################################################
load(file='quadprog.Rdata')
# solve QP using quadprog
require(quadprog)
sol = solve.QP(Dmat, dvec, Amat, bvec, meq)
x = sol$solution
check = x %*% Amat - bvec
# for some reason last equality constraint is violated
round(check[1:meq], 4)
# solve QP using kernlab
require(kernlab)
n = nrow(Amat)
sv = ipop(c = matrix(dvec), H = Dmat, A = t(Amat[,1:meq]),
b = bvec[1:meq], l = rep(-1000,...
2007 Jul 02
0
relocation error in grDevices.so
...old installation:
import numpy
import rpy
rpy.r("library(quadprog)")
Dmat = numpy.identity(3, numpy.float_)
print Dmat
rpy.r.assign("Dmat", Dmat)
dvec = numpy.array([0,5,0], numpy.float_)
print dvec
rpy.r.assign("dvec", dvec)
Amat = numpy.array([[-4,-3,0], [2,1,0], [0,-2,1]], numpy.float_)
print Amat
rpy.r.assign("Amat", Amat.transpose())
bvec = numpy.array([-8,2,0], numpy.float_)
print bvec
rpy.r.assign("bvec", bvec)
result = rpy.r("solve.QP(Dmat, dvec, Amat, bvec=bvec)&quo...
2005 Dec 14
6
mysql connection problems
Hi
hi i have a problem trying to connect to the mysql database when I do a
rake it says: Access denied for user: ''@localhost'' to database ''''
My database.yml file is fine
Any ideas why this is happening
--
Posted via http://www.ruby-forum.com/.
2010 Dec 04
1
Quadratic programming with semi-definite matrix
...re there any (fast) packages
that allows me to do QP with (large) semidefinite matrices?
Example:
t <- 100
y <- signalConvNoisy[1,]
D <- crossprod(H,H)
d <- crossprod(H,y)
A <- cbind(rep(-1, nrow(H)), diag(ncol(H)))
b0 <- c(t, rep(0, ncol(H)))
sol <- solve.QP(Dmat=D, dvec = d, Amat = A, bvec = b0)$solution
Error in solve.QP(Dmat = D, dvec = d, Amat = A, bvec = b0) :
matrix D in quadratic function is not positive definite!
Thanks in advance,
Andreas Jensen
2010 Dec 06
1
use pcls to solve least square fitting with constraints
Hi,
I have a least square fitting problem with linear inequality
constraints. pcls seems capable of solving it so I tried it,
unfortunately, it is stuck with the following error:
> M <- list()
> M$y = Dmat[,1]
> M$X = Cmat
> M$Ain = as.matrix(Amat)
> M$bin = rep(0, dim(Amat)[1])
> M$p=qr.solve(as.matrix(Cmat), Dmat[,1])
> M$w = rep(1, length(M$y))
> M$C = matrix(0,0,0)
> p<-pcls(M)
Error in t(qr.qty(qra, t(M$X))[(j + 1):k, ]) :
error in evaluating the argument 'x' in selecting a method for function 't'
Af...
2008 May 08
0
solve.QP() error
I got following error while I was using solve.QP() in my problem:
> Dmat = matrix(c(0.0001741, 0.0001280, 0.0001280, 0.0002570), nrow=2)
> dvec = t(c(0,0))
> Amat = matrix(c(-1,1,0,-1,0, 1,0,1,0,-1), nrow=5)
> bvec = c(-20000, 1, 1, -50000, -50000)
> solve.QP(Dmat,dvec,Amat,bvec=bvec)
Error in solve.QP(Dmat, dvec, Amat, bvec = bvec) :
Amat and dvec are incompatible!
>
Can anyone tell me where is the error in my definition?
Regards,...
2012 Jul 12
1
SVAR Restriction on AB-model
Hello!
I'm doing a svar and when I make the estimation the next error message
appears:
In SVAR(x, Amat = amat, Bmat = bmat, start = NULL, max.iter = 1000, :
The AB-model is just identified. No test possible.
Could you help me to interpret it please.
Also I have the identification assumption that one of my shocks is exogenous
relative to the contemporaneous values of the other variables in the S...