R help - Mar 2006 - Constrained least squares

Is there a function in R for constrained linear least squares?

I used the matlab function LSQLIN: my aim is to obtain
non-negative regression coefficients which sum 1.

Thanks in advance,
domenico vistocco


	

	
		
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Domenico Vistocco <vistocco <at> unicas.it> writes:
> 
> Is there a function in R for constrained linear least squares?
> 
> I used the matlab function LSQLIN: my aim is to obtain
> non-negative regression coefficients which sum 1.
> 
> Thanks in advance,
> domenico vistocco
  I haven't tried it, but it looks like constrOptim()
[plus your own objective function that calculates sums of squares,
something like

f <- function(param1,param2) {
   y.exp <- ... [function of param1 and param2]
   sum((y.exp-y)^2)
}

(or substitute -sum(dnorm(y,mean=y.exp,sd=param3,log=TRUE)) for
the last line)