Displaying 20 results from an estimated 3000 matches similar to: "Solver in R"
2011 Apr 23
2
Loop and Solver with Black/Scholes-Formula
Hello,
for my diploma thesis I need to program a solver for Merton?s respectively
Black?s and Scholes? Option pricing formula, which should be achieved for
several dates.
What I want to do is to estimate the value of a firm?s assets "vA" (x[2]
denotes vA) and the option-implied volatility of firm?s assets "sigA" (x[1]
denotes sigA) by solving it simultaneous using the Black
2010 Nov 21
1
solve nonlinear equation using BBsolve
Hi r-users,
I would like to solve system of nonlinear equation using BBsolve function and
below is my code. I have 4 parameters and I have 4 eqns.
mgf_gammasum <- function(p)
{
t <- rep(NA, length(p))
mn <- 142.36
vr <- 9335.69
sk <- 0.8139635
kur <- 3.252591
rh <- 0.896
# cumulants
k1 <- p[1]*(p[2]+p[3])
k2 <- p[1]*(2*p[2]*p[3]*p[4] +p[2]^2+p[3]^2)
k3 <-
2010 Jul 29
7
newton.method
Hi,
Is this method broken in R? I am using it to find roots of the following
function:
f(x) = 2.5*exp(-0.5*(2*0.045 - x)) + 2.5*exp(-0.045) + 2.5*exp(-1.5*x) - 100
It is giving an answer of -38.4762403 which is not even close (f(x) =
2.903809e+25 for x=-38.4762403). The answer should be around 0.01-0.1. This
function should converge..
Even for a simple function like f(x) = exp(-x) * x, it gives
2012 Dec 11
1
Solving Simultaneous nonlinear equations
Dear:
I am having trouble solving simultaneous nonlinear equations by R. I have
been using BBsolve (BB) to do so. Though the function is very strong, still
the program doesn't converge. I have tried all (according to my small
knowledge) the options described in the help file.
Now I am trying to find something else than BBsolve for solving
simultaneous nonlinear equations by R. Any idea or
2010 Sep 26
2
Finding Zeros of a Function
Dear All,
I need to find the (possible multiple) zeros of a function f within an
interval. I gave uniroot a try, but it just returns one zero and I need
to provide it with an interval [a,b] such that f(a)f(b)<0.
Is there any function to find the multiple zeros of f in (a,b) without
constraints on the sign of f(a) and f(b)?
Many thanks
Lorenzo
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
2009 Oct 11
1
Solving a nonlinear System of equations
Hello there,
I wish to solve the following nonlinear System of equations:
+ u1 - Vmax11*S1/(S1 + Km11 *(1 + S2/Km21)) - Vmax12*S1/( S1 + Km12 *(1+S2/Km22)) == 0
+ u2 - Vmax22*S2/(S2 + Km22 *(1 + S1/Km12)) - Vmax21*S2/( S2 + Km21 *(1+S1/Km11)) == 0
+ Vmax11*S1/(S1 + Km11 *(1 + S2/Km21)) + Vmax12*S1/( S1 + Km12 *(1+S2/Km22)) - d1*P1 == 0
+ Vmax22*S2/(S2 + Km22 *(1 + S1/Km12)) + Vmax21*S2/( S2 +
2011 Dec 19
1
None-linear equality constrained optimisation problems
Dear R users,
I have a problem. I would like to solve the following:
I have
pL = 1/(1+e^(-b0+b1))
pM = 1/(1+e^(-b0))
pH = 1/(1+e^(-b0-b1))
My target function is
TF= mean(pL,pM,pH) which must equal 0.5%
My non-linear constraint is
nl.Const = 1-(pM/pH), which must equal 20%, and would like the values of
both b0 and b1 where these conditions are met.
I have searched widely for an answer,
2017 Jun 11
1
Memory leak in nleqslv()
Hello all,
I am relatively new to R, but enjoying it very much. I am hoping that
someone on this list can help me with an issue I am having.
I am having issues with iterations over nleqslv, in that the solver
does not appear to clean up memory used in previous iterations. I
believe I've isolated the/my issue in a small sample of code:
library(nleqslv)
cons_ext_test <- function(x){
2010 Mar 11
4
help about solving two equations
I have two matrix s1 and s2, each of them is 1000*1.
and I have two equations:
digamma(p)-digamma(p+q)=s1,
digamma(q)-digamma(p+q)=s2,
and I want to sovle these two equations to get the value of x and y, which are also two 1000*1 matrices.
I write a program like this:
f <- function(x) {
p<- x[1]; q <- x[2];
((digamma(p)-digamma(p+q)-s1[2,]) )^2 +((digamma(q)-digamma(p+q)-s2[2,]) )^2
2008 Oct 04
1
back-solver: any R thing like TK!Solver?
Just thought I'd ask. For those who've never seen TK!Solver, I strongly
recommend taking a look. So far as I can tell, it's the only product of
its type available, retail or open source, for any platform.
What makes TK!Solver so cool is that it adaptively back-solves pretty
much any unknown from any set of equations you give it. (or vector full
of unknowns, producing a vector of
2009 Feb 08
3
general inverse solver?
Just wondering if there's an R package which does tricks similar to what
TK!Solver does.
TK!Solver, for those not lucky enough to have found it, basically allows
one to define a bunch of equations, assign values to an arbitrary subset
of the variables, from which it calculates (either directly when
possible or back-solving when not) the values of the other variable(s).
thanks
Carl
2008 Oct 05
1
Excel Solver Add-In / Alternatives
Hi,
I can't seem to get any Excel Add-Ins to work. In particular, I need the 'Solver' for an assignment ...
I've tried with two office versions (2007/2003), which I've managed to install successfully (you have to enable the Solver add-in during installation), but it's the same every time.
When I try to start it up I get a message saying can't access SOLVER.XLA, and
2009 Jul 08
2
i need same function solver in excel..
hi..
i used R a few days..
who can call me? same function solver in excel.
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2007 Dec 13
1
[LLVMdev] Puzzle solver on LLVM 2.1
Dear guys,
I've put the puzzle solver running on LLVM 2.1. Well, at least
partially, for it is failing three of SPEC2000 benchmarks. I will try to
debug it now. The results are not as good as before. I mean, the puzzle
solver is still the same, but the default allocator is producing very good
code now. Even though, the puzzle solver produces faster code for half the
benchmarks. It
2012 Jul 18
1
Defining a variable outside of optim or differential equation solver.
This is applicable to either using optim or the differential equation
solver or any similar solver
Suppose I want to use the differential equation solver and this is my code
d<-y[2]
vdpol<-function(t,y)
{
list(c(1,
d,
3,
4
)
}
stiff<-ode(y=rep(0,4),times=c(0,1),func=dvdpol,parms=1)
The thing is I want d to be composed of one of state variables in the
2011 Nov 07
2
How to do a target value search analogous to Excel Solver
Hi all,
i'm trying to find a solver possibility analogous to the Excel Solver in R.
Since i just started with R, I have only little knowledge. Can someone help
me by solving the problem?
I have the following 'starting position':
z = rnorm(1,0,1)
y <- function(x,z){2*x - 1 + z}
I am looking for a certain "x" in such a way that the result of the function
'y'
2013 Feb 20
2
'gmm' package: How to pass controls to a numerical solver used in the gmm() function?
Hello --
The question I have is about the gmm() function from the 'gmm' package
(v. 1.4-5).
The manual accompanying the package says that the gmm() function is
programmed to use either of four numerical solvers -- optim, optimize,
constrOptim, or nlminb -- for the minimization of the GMM objective
function.
I wonder whether there is a way to pass controls to a solver used
while calling
2004 Jan 14
2
nonlinear regression and Excel solver
Hi all,
Earlier today I posted this question on s-news, so apologies to some for
the duplication.
> Please put aside your snobbery about Microsoft products for a moment.
>
> I am fitting population models to annual survey data for trout. For those of you familiar with ecological models, I am working in the Lefkovitch matrix framework; for those unfamiliar with that shorthand, the
2012 Jan 08
2
R package equivalent to Excel SOLVER - Paquete R equivalente a SOLVER de Excel
Esteemed colleagues
I wonder if there is a package in R that performs the functions of the
Excel SOLVER.
Thanks in advance for the reply.
Best regards,
-------------------------
Estimados colegas
Me pregunto si hay un paquete en R que funcione como el SOLVER de Excel.
De antemano gracias por la respuesta.
Saludos,
--
Ricardo Bandin Llanos
rbandin@udec.cl
[c] Magíster Cs. m. Pesquerías