Dear All, The function I wrote can run well with the small data, but with the large data, the function runs very very slowly. How can I correct it? Thank you very much. My function as below:
a<-c(1:240) b<-c(1:240) l=function(a,b){ v=0 u=0 uv=0 v[1]=0 u[1]=0 uv[1]=0 for (i in 1:(length(s)-1)){ v[i]<-((gx[[i]][b,(gx[[i]][a,1]+1)])-(gx[[i]][a,gx[[i]][a,1]+1]))/(gx[[i]][a,gx[[i]][a,1]+1]) u[i]<-((gy[[i]][a,(gy[[i]][a,1]+1)])-(gy[[i]][b,gy[[i]][a,1]+1]))/(gy[[i]][a,gy[[i]][a,1]+1]) uv[i]<-v[i]+u[i] } w=0 w=mean(uv) } kk<-data.frame() for (a in 1:240){ for (b in 1:240){ if (a<b) kk[a,b]=l(a,b) else kk[a,b]=0 }} max(kk) -- View this message in context: http://r.789695.n4.nabble.com/For-calculation-is-so-slow-tp4630830.html Sent from the R help mailing list archive at Nabble.com. ______________________________________________ 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.