Hi:
On Wed, Feb 9, 2011 at 6:29 AM, Claudio Carneiro <
claudio_carneiro...@hotmail.com> wrote:
>
> Hi, all
>
> I'm trying to solve an optimization problem with two
> variables, in wich Iuse the following functions(they all are working
> perfectly):
>
> fxx1=function(x){
> calc=((2.5/3)*((x/3)^(2.5-1))*exp(-(x/3)^2.5))
> return(calc)}
>
> fxx2=function(x){
> calc1=((5.3/19.3)*((x/19.3)^(5.3-1))*exp(-(x/19.3)^5.3))
> return(calc1)}
>
> fxMixed=function(x){
> calc2=(0.12*fxx1(x)+((1-0.12)*fxx2(x)))
> return(calc2)}
>
>
> FxMixed=function(x){
> calc3=integrate(fxMixed,0,x)
> return(calc3$value)}
>
> RxMixed=function(x){
> calc4=(1-FxMixed(x))
> return(calc4)}
>
> SUM=function(x){
> T1=x[1]
> M1=x[2]
> n=M1-1
> calc5=1:n
> for (i in 0:n){
> calc5[i]=RxMixed(i*T1)}
> sum(calc5)}
>
> V=function(x){
> T1=x[1]
> M1=x[2]
> y=T1*M1
> calc6=T1*SUM(x)+0.001*RxMixed(y)+0.00463*FxMixed(y)
> return(calc6)}
>
> However, when I try to use the function U, there is an error message and I
> don't understand what's wrong with my code:
>
> U=function(x){
> T1=x[1]
> M1=x[2]
> y=M1*T1
> calc7=integrate(RxMixed,0,y)
> return(calc7$value)}
> > U(c(2,5))
> Error in integrate(RxMixed, 0, y) :
> evaluation of function gave a result of wrong length
>
>
>
> I think that this might happen becouse my fucntion RxMixed is already an
> previous integration of the function fxMixed.
>
I concur. RxMixed is a number, not a function - integrate() requires the
latter. It appears that RxMixed is the survival function of a mixture
distribution - you need to either get a symbolic representation of that
function or generate a function numerically by computing RxMixed over a
suitable range of x values and then using something like approxfun() or
splinefun() to estimate the survival function. You could then integrate the
resulting function in U.
HTH,
Dennis
>
> Any help will be welcome!
>
>
> [[alternative HTML version deleted]]
>
> ______________________________________________
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> and provide commented, minimal, self-contained, reproducible code.
>
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