Hello.  I had previously posted a question concerning the optimization
of a nonlinear function conditional on equality constraints.  I was
pointed towards the contrOptim function.  However, I do not understand
the syntax of this function with respect to specifying the constraints
and so I don�t know if it is what I need.  The command is:

constrOptim(theta, f, grad,ui,ci,�).  �theta� is the initial value of
the variables in the function, �f� and �grad� are the function to be
optimized and its gradient functions (partial deriviatives).  Now, �ui�
and �ci� are stated to be constraints in the help documentation but it
is not explained how these constraints are to be specified.  To be
concrete, here is my objective function:

 

f<- -1*pi*log(pi)  i.e. the entropy of a vector of probabilities (pi)

 

The constraints are the first moments of the distribution:

 

C1=sum(k1*pi); C2<-sum(k2*pi); etc.

 

Any help is appreciated.

 

Bill Shipley

Associate Editor, Ecology

North American Editor, Annals of Botany

D�partement de biologie, Universit� de Sherbrooke,

Sherbrooke (Qu�bec) J1K 2R1 CANADA

[EMAIL PROTECTED]

 <http://callisto.si.usherb.ca:8080/bshipley/>
http://callisto.si.usherb.ca:8080/bshipley/

 


        [[alternative HTML version deleted]]

______________________________________________
[EMAIL PROTECTED] mailing list
https://www.stat.math.ethz.ch/mailman/listinfo/r-help

Reply via email to