For my problem I have #Constraints b11<-0 b21<-0 b12<-0 b22<-0 n1>=0 n2>=0 n1<=1 n1<=1 n1+n2=1 In order to use spg I set Amat<-matrix(rbind(c(rep(0,10)),c(rep(0,10)),c(rep(0,2),1,rep(0,7)), c(rep(0,3),1,rep(0,6)),c(rep(0,10)),c(rep(0,10)), c(rep(0,6),1,rep(0,3)),c(rep(0,7),1,rep(0,2)), c(rep(0,8),1,rep(0,1)),c(rep(0,9),1,rep(0,0)), c(rep(0,8),1,rep(0,1)),c(rep(0,9),1,rep(0,0)), c(rep(0,8),1,1)),ncol=10) b<-c(rep(0,4),rep(0,4),0,0,-1,-1,-1) meq<-c(seq(1:8),13) #1:8 &13 condition is an equality Although spg gives "Successful convergence" it also gives the message: There were 50 or more warnings (use warnings() to see the first 50) Warning messages: 1: In if (meq > 0 | any(b - c(A %*% par) > 0)) { ... : the condition has length > 1 and only the first element will be used How must I denote meq to be sure that algorithm takes into account the conditions 1:8 &13 as equality and only conditions 9:12 as inequalities? Thanks -- View this message in context: http://r.789695.n4.nabble.com/definition-of-meq-at-spg-tp3560285p3560285.html Sent from the R help mailing list archive at Nabble.com.