R help - Oct 2004 - Puzzled on nlm

Dear R People:

Here is a function to minimized:
>mfun1
function(x,a) {
  x[1] <- a[1]*x[2] + a[3] - a[2]*(a[1]-a[2])*a[3]
  x[2] <- a[1]*x[1] - a[2]*a[3]
  return(x)
}

Here is my first try:
>nlm(mfun1,c(1,1))
Error in f(x, ...) : Argument "a" is missing, with no
default
>
>nlm(mfun1,c(1,1),a=c(0.8,0.5,1))
Error in nlm(mfun1, c(1, 1), a = c(0.8, 0.5, 1)) :
        invalid function value in 'nlm'
optimizer
>
I am stumped.  I'm sure that it's something really small that I'm 
overlooking.

Thanks in advance for any help.

Sincerely,
Laura Holt
mailto: lauraholt_983 at hotmail.com

Laura Holt wrote:
> Dear R People:
> 
> Here is a function to minimized:
> 
>> mfun1
> 
> function(x,a) {
>  x[1] <- a[1]*x[2] + a[3] - a[2]*(a[1]-a[2])*a[3]
>  x[2] <- a[1]*x[1] - a[2]*a[3]
>  return(x)
> }
> 
> Here is my first try:
> 
>> nlm(mfun1,c(1,1))
> 
> Error in f(x, ...) : Argument "a" is missing, with no default
> 
>>
> 
>> nlm(mfun1,c(1,1),a=c(0.8,0.5,1))
> 
> Error in nlm(mfun1, c(1, 1), a = c(0.8, 0.5, 1)) :
>        invalid function value in 'nlm' optimizer
You function returns a vector of length two, but nlm() expects length 
one (what is the minimum, otherwise?).

Uwe Ligges

>>
> 
> I am stumped.  I'm sure that it's something really small that
I'm
> overlooking.
> 
> Thanks in advance for any help.
> 
> Sincerely,
> Laura Holt
> mailto: lauraholt_983 at hotmail.com
> 
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