similar to: Non-linear system of equations

Displaying 20 results from an estimated 300 matches similar to: "Non-linear system of equations"

2011 Mar 10
2
R beginner - Error in as.vector(x, mode)
Hi everyone, I am new to R and keep getting the message Error in as.vector(x, mode) while trying to run nlsystemfit. Below is my exact code. The data is in Stata format because I only recently swapped to R and am trying to compare results from Stata to make sure I know what is going on. I have searched google and read sever R-help articles with this error. They all say the problem is to do
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
2006 Jan 12
1
Problem with NLSYSTEMFIT()
Hello, I want to solve a nonlinear 3SLS problem with "nlsystemfit()". The equations are of the form y_it = f_i(x,t,theta) The functions f_i(.) have to be formulated as R-functions. When invoking "nlsystemfit()" I get the error Error in deriv.formula(eqns[[i]], names(parmnames)) : Function 'f1' is not in the derivatives table
2010 Jan 09
2
Functions for QUAIDS and nonlinear SUR?
Hi, I would like to estimate a quadratic almost ideal demand system in R which is estimated usually by nonlinear seemingly unrelated regression. But there is no such function in R yet but it is readily available in STATA (nlsur), see B. Poi (2008): Demand-system estimation: Update, Stata Journal 8(4). Now I am thinking, what is quicker learning to "program" STATA which seems not really
2004 Jan 20
2
Error: unknown identifier {|} in tabular format {|l|c|c|c|}
I've got a package I would like to send out for testing and have noticed a "problem" with the \tabular portion of the help "compiler" the code for inserting vertical lines, in the tabular environment, causes the build to choke, but not the check command. C:\>rcmd build --binary -docs=all nlsystemfit \tabular{|l|c|c|c|}{ \hline Method \tab Instruments \tab
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
2012 Nov 20
1
Coefficient of determination for non-linear equations system (nlsystemfit)
Hello everyone, I have estimated system of three linear equations with one non-linear restrictions with nlsystemfit. I was wondering how I can calculate the R-squared (or some alternative coefficient of determination) for the whole system. This is automatically given by linear systemfit but not by nlsystemfit. I can get the values for each of the equations separately, but apparently not for
2007 Feb 25
1
nested design in lme, need help with specifying model
Hi, I wonder if anyone can help me with specifying a right model for my analysis. I am a beginner to lme methods and though have spent already many hours studying from various books an on-line helps, I was unfortunately not able to find a solution to my problem on my own. Data structure: I studied escape behavior of three species of a prey to a predator. The prey specimens (many) were in a
2010 May 14
2
Subscripting a matrix-like object
I have an S3 class called "tis" (Time Indexed Series) which may or may not have multiple columns. I have a function "[<-.tis" that I've reproduced below. My question is this: inside of "[<-.tis", how can I distinguish between calls of the form x[i] <- someValue and x[i,] <- someValue ? In either case, nargs() is 3, and looking at the values
2010 May 14
2
Subscripting a matrix-like object
I have an S3 class called "tis" (Time Indexed Series) which may or may not have multiple columns. I have a function "[<-.tis" that I've reproduced below. My question is this: inside of "[<-.tis", how can I distinguish between calls of the form x[i] <- someValue and x[i,] <- someValue ? In either case, nargs() is 3, and looking at the values
2011 Dec 11
1
nls start values
I'm using nls to fit periodic gene-expression data to sine waves. I need to set the upper and lower boundaries, because I do not want any negative phase and amplitude solutions. This means that I have to use the "port" algorithm. The problem is, that depending on what start value I choose for phase, the fit works for some cases, but not for others. In the example below, the fit works
2004 Feb 05
1
Installing odesolve under MacOSX
Installing odesolve in Raqua 1.8.0 or 1.8.1 under MacOSX gives the following message: Warning message: Installation of package odesolve had non-zero exit status in: install.packages(ui.pkgs, CRAN = getOption(where), lib = .libPaths()[1]) Moreover, in the source of odesolve is no makefile. Does anyone know how to get a proper installation? Maartje
2007 Jul 13
2
nearest correlation to polychoric
Dear all, Has someone implemented in R (or any other language) Knol DL, ten Berge JMF. Least-squares approximation of an improper correlation matrix by a proper one. Psychometrika, 1989, 54, 53-61. or any other similar algorithm? Best regards Jens Oehlschl?gel Background: I want to factanal() matrices of polychoric correlations which have negative eigenvalue. I coded Highham 2002
2008 Nov 20
1
Nonlinear restrictions in systemfit
Hey, I want to implement a structural model with the package systemfit with some linear and nonlinear constraints. How to implement linear restrictions is clear. Does anybody know how to set up nonlinear restrictions in the systemfit packages. For example: beta1 = beta2-(beta4/beta6) I look forward to your reply -- View this message in context:
2011 Aug 20
4
[PATCH 1/2] Make xencommons a bit more idiomatic
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> diff -r 8d6edc3d26d2 -r cfb49fe940fd tools/hotplug/Linux/init.d/xencommons --- a/tools/hotplug/Linux/init.d/xencommons Sat Aug 13 10:14:58 2011 +0100 +++ b/tools/hotplug/Linux/init.d/xencommons Tue Aug 16 16:56:16 2011 -0700 @@ -29,11 +29,9 @@ XENCONSOLED_PIDFILE=/var/run/xenconsoled.pid shopt -s extglob -if test
2010 Apr 29
1
BB package
Hi I would like to solve a system of nonlinear equations below using dfsane function   mn <- 142.36; vr <- 9335.69 ; sk <- 0.81;  kur <- 0.25 test_fn <- function(p) {    f <- rep(NA, length(p))     f[1] <- p[1]*(p [2]+p[3])- mn   f[2] <- - vr + 2*p[1]*p[2]*p[3]*(p[4]-1)+p[1]*(p[2]+p[3])^2   f[3] <- - sk + (p[1]*(p [2]+p[3])^3*(p[1]+1)*(p[1]+2)-6*p[1]*p[2]*p[3]*(p[2]+
2015 Sep 15
4
Fwd: problema en while y en extraer valores de un vector
> > >> >> Hola a todos, >> >> es la primera pregunta que hago a esta lista, no se si estoy en el sitio correcto. >> >> Tengo el siguiente vector: >> >> a <- c(8,10,4,1,7,2,4,6,3,8) >> >> y quiero conseguir en pantalla 5 valores, empezando por el final, y recorriendo el vector de derecha i izquierda cada vez, es decir,
2006 Mar 26
2
Problem with names() in a plot after ordering a data.frame. Syntax or stupidity?
I am a complete newbie in R . Using R 2.2.0 Windows XP This started as a simple exercise to see if I could produce a simple Cleveland style dotchart with a line from the '2' axis to the dot rather than a continuous line as do "dotchart" and "dotchart2". At least I could not find that option. I got a crude program to work but it includes unnecessary steps.
2008 Jun 03
3
How to solve a non-linear system of equations using R
Dear R-list members, I've had a hard time trying to solve a non-linear system (nls) of equations which structure for the equation i, i=1,...,4, is as follows: f_i(d_1,d_2,d_3,d_4)-k_i(l,m,s) = 0 (1) In the expression above, both f_i and k_i are known functions and l, m and s are known constants. I would like to estimate the vector d=(d_1,d_2,d_3,d_4) which is solution
2011 Aug 20
3
[PATCH 2/2] Load gntdev and evtchn if they''re modular.
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> diff -r cfb49fe940fd -r 81f75ed45ec2 tools/hotplug/Linux/init.d/xencommons --- a/tools/hotplug/Linux/init.d/xencommons Tue Aug 16 16:56:16 2011 -0700 +++ b/tools/hotplug/Linux/init.d/xencommons Tue Aug 16 17:05:18 2011 -0700 @@ -29,12 +29,18 @@ XENCONSOLED_PIDFILE=/var/run/xenconsoled.pid shopt -s extglob -if [