Hi, I would like to write a function for this formula: F(a,b,c,z)=1+(ab)/(1!c)+ +(a(a+1)b(b+1))/(2!c(c+1))+ +(a(a+1)(a+2)b(b+1)(b+2))/(3!c(c+1)(c+2))+… I wrote this function but not sure what is not right: hypergeo_sum <- function (a,b,c,z,n) { for (i in 1:n) { aa <- 1+(a*b*z)/c aa[i] <- (aa-1)*(a+i)*(b+i)*z/((i+1)*(c+i)) comb_sum <- aa + aa[i]+ aa[i+2] } comb_sum } hypergeo_sum (1.25,1.75,1.25,0.5,3) output: > hypergeo_sum (1.25,1.75,1.25,0.5,3) [1] 2.394531 NA 1.039062
The answer should be 2.852539. Or can you suggest any R book that I can refer to. Thank you so much for your help. ______________________________________________ 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.