Please read the Posting Guide no html email reproducible example please In general, you can use expand.grid to generate all combinations of inputs, compute results as a vector just as long as the expand.grid data frame has rows, and identify which results meet your criteria by a logical test, and use that test to identify which input combinations worked. Provide a working starting point and someone might give you working code as an answer. (where do a and b come into your problem?) --------------------------------------------------------------------------- Jeff Newmiller The ..... ..... Go Live... DCN:<jdnew...@dcn.davis.ca.us> Basics: ##.#. ##.#. Live Go... Live: OO#.. Dead: OO#.. Playing Research Engineer (Solar/Batteries O.O#. #.O#. with /Software/Embedded Controllers) .OO#. .OO#. rocks...1k --------------------------------------------------------------------------- Sent from my phone. Please excuse my brevity.
Andras Farkas <motyoc...@yahoo.com> wrote: >Dear All >� >I have the following data (somewhat simplyfied): >� >TINF <-1 >a <-c(500,750,1000,1250,1500,1750,2000) >b <-c(8,12,18,24,36,48,60,72,96) >� >following function: >� >infcprodessa <-function (D, tin, tau, ts) >� (D * (1 - exp(-0.048 * tin))/(tin * (0.048*79) * (1 - exp(-0.048 * >tau)))) * exp(-0.048 * (ts - tin)) > >z <-sapply(1:1, function(n) infcprodessa(1000,TINF,12,12-TINF)) >� >is there a way to select the combination of respective a and b values >that would result in a calculated z that is between 15 and 20? In this >case the a would be 1000 and the b would be 12 (other combinations are >also possible), but how could I automatically find them? perhaps a >loop? >� >Apreciate the help, >� >Sincerely, >� >Andras > [[alternative HTML version deleted]] > > > >------------------------------------------------------------------------ > >______________________________________________ >R-help@r-project.org mailing list >https://stat.ethz.ch/mailman/listinfo/r-help >PLEASE do read the posting guide >http://www.R-project.org/posting-guide.html >and provide commented, minimal, self-contained, reproducible code. ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.