Hello, I did a function (sec_conop) whose arguments are syndic, well and wellconop. sec_conop(syndic='01syndic.txt',well='well-1.csv',wellconop='well-1.dat');closeAllConnections() This function takes ?well? and ?syndic?, matching between them and then it does some transformations. The result is exported to ?wellconop?. I will apply this function to one hundred different ?wells?. Therefore, for each well I use, the ?wellconop argument will change too. For intance if ?well? is now well-2.csv, the function will be sec_conop(syndic='01syndic.txt',well='well-2.csv',wellconop='well-2.dat');closeAllConnections() I am trying to apply this function automatically to all ?well? I have, but I do not find the way. The last I tried, for three different ?wells?, was : wells<-data.frame(funct=rep('sec_conop(',3),syndic=c('01syndic.txt','01syndic.txt','01syndic.txt'),well=c('well-1.csv','well-2.csv','well-3-1.csv'),wellconop=c('well-1.dat','well-2.dat','well-3.dat')) funct_3wells<-paste(wells$funct,"'",wells$syndic,"'", "," ,"'", wells$well,"'", "," , "'" ,wells$wellconop,"'",")",";","closeAllConnections()",sep='') lapply(funct_3wells,as.formula) This way works partially because the results in ?wellconop? are truncated. Has anyone any suggestion? Thanks in advance Carlos