# Loop question? Classic List Threaded 6 messages Open this post in threaded view
|

## Loop question?

 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]] ______________________________________________ [hidden email] mailing list https://stat.ethz.ch/mailman/listinfo/r-helpPLEASE do read the posting guide http://www.R-project.org/posting-guide.htmland provide commented, minimal, self-contained, reproducible code.
Open this post in threaded view
|

## Re: Loop question?

Open this post in threaded view
|

## Re: Loop question?

 In reply to this post by Andras Farkas Here's a toy example which you can apply the logic of: dfr <- expand.grid(1:3,1:2) results <- apply(dfr, 1, sum) dfr[results==4,] On 25 January 2013 22:19, Andras Farkas <[hidden email]> 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]] > > > ______________________________________________ > [hidden email] 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. > ______________________________________________ [hidden email] mailing list https://stat.ethz.ch/mailman/listinfo/r-helpPLEASE do read the posting guide http://www.R-project.org/posting-guide.htmland provide commented, minimal, self-contained, reproducible code.
Open this post in threaded view
|