Displaying 4 results from an estimated 4 matches for "mybeta".
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nybeta
2008 May 10
2
substitute in graphics - Uwe's help desk
Un texte encapsul? et encod? dans un jeu de caract?res inconnu a ?t? nettoy?...
Nom : non disponible
URL : <https://stat.ethz.ch/pipermail/r-help/attachments/20080510/28c07d4e/attachment.pl>
2011 Nov 10
3
optim seems to be finding a local minimum
...regression with a single predictor:
mysum<- function(myIV,myDV){
regr<-lm(myDV[[1]] ~ 0 + myIV[[1]])
mysum<-sum(abs(regr$resid))
return(mysum)
}
### Function to be optimized;
### param is a vector of 2 values (.alpha and .beta)
myfunc <- function(param){
myalpha<-param[1]
mybeta<-param[2]
IVtransf<-transformIV(myalpha, mybeta)
sumofdevs<-mysum(myIV=IVtransf,myDV=DV)
return(sumofdevs)
}
# Optimizing using optim:
myopt <- optim(fn=myfunc, par=c(0.1,max(IV)), method="L-BFGS-B", lower=0)
(myopt)
myfunc(myopt$par)
## Comparing this solution to Excel...
2008 May 09
1
substitute in graphics
Un texte encapsul? et encod? dans un jeu de caract?res inconnu a ?t? nettoy?...
Nom : non disponible
URL : <https://stat.ethz.ch/pipermail/r-help/attachments/20080509/4eaa6b46/attachment.pl>
2007 Jun 06
3
Using odesolve to produce non-negative solutions
...Thanks,
Jeremy
P.S., Below is a simplified version of the code I use to try to do this, but I am not sure that it is theoretically right
dynmodel <- function(t,y,p)
{
## Initialize parameter values
birth <- p$mybirth(t)
death <- p$mydeath(t)
recover <- p$myrecover
beta <- p$mybeta
vaxeff <- p$myvaxeff
vaccinated <- p$myvax(t)
vax <- vaxeff*vaccinated/100
## If the state currently has negative quantities (shouldn't have), then reset to reasonable values for computing meaningful derivatives
for (i in 1:length(y)) {
if (y[i]<0) {
y[i] <- 0
}
}...