Dear R-users, May I seek some suggestions from you. I have a long programme written in R with several 'for' loops inside. I just want to get them out by any elegant way (if there is!) to reduce the computational time of the main programme. For instance, is there any smart way for the following programme that will lessen time?
--------------------------------------------------------------------------------------------------------------- dose<-seq(0,10,.5) alpha1<--4 beta1<-0.5 alpha2<--6 beta2<--.7 psi1<-function(alpha1,beta1,alpha2,beta2,d){ z1<-exp(alpha1+beta1*d) z2<-exp(alpha2+beta2*d) z1/((1+z1)*(1+z2)) } psi2<-function(alpha2,beta2,d) { z2<-exp(alpha2+beta2*d) z2/(1+z2) } psi1.hat=c() psi2.hat=c() for (i in 1:length(dose)){ # just want to avoid this 'for' loop d<-dose[i] psi1.hat[i]<-psi1(alpha1,beta1,alpha2,beta2,d) psi2.hat[i]<-psi2(alpha2,beta2,d) } print(psi1.hat) print(psi2.hat) ------------------------------------------------------------------------------------------------------------ Many thanks for your kind attention. Regards, Jamil. [[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.