search for: bozhao86

Hi all, I wrote the following lines of codes try to do some iterations to find the global optimal values, but the function does not execute properly. Every time codes stop after one iteration right after executing the optim() function. Does anyone could have me to take a look? Thanks. if (count>0){ k=k+0.05; mu0=c(83+k,0,0) Sigma0= diag(0.4,3) initpar=c(.1+10*k,10*k,10*k,10*k) # initial

Hi all, I have a huge dataset(5000k observations), which contains the daily sales for each company. If I want to find out the a company with unique company id number, which function I should use that is more efficient, match or "=="? For example, use<-dataset[!is.na(match(dataset$companyID, 12345)),] or use<-dataset[dataset$companyID==12345,] Thank you very much. -- View this