Dear R users,

I have a problem. I would like to solve the following:

I have

pL = 1/(1+e^(-b0+b1))

pM = 1/(1+e^(-b0))

pH = 1/(1+e^(-b0-b1))

My target function is

TF= mean(pL,pM,pH) which must equal 0.5%

My non-linear constraint is

nl.Const = 1-(pM/pH), which must equal 20%, and would like the values of
both b0 and b1 where these conditions are met.

I have searched widely for an answer, and did think that Rdonlp2 would
suffice, only to find it no longer supported. I have solved this using
Excel's solver function, however, because of the non-linear constraint I am
having problems finding the solution in R.

Can the community suggest another method by which this might be solved?

As ever, many thanks for your time.

Mike Griffiths


-- 

*Michael Griffiths, Ph.D
*Statistician

*Upstream Systems*

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