# distribuzione t di Student: quantili (test a due code)

job <- function(df,p) qt(p,df,lower.tail=FALSE)
glib <- c(1:50)
pval <- c(0.1,0.05,0.025,0.01,0.005,0.001)
qntl <- outer(glib,pval/2,job) # notare l'uso della funzione outer
                               # e il dimezzamento della probabilità
                               # per un test a due code

tbl <- round(qntl,3)
nr <- nrow(tbl)+1
nc <- ncol(tbl)+1
out <- matrix(NA,nr,nc)
out[2:nr,2:nc] <- tbl
out[2:nr,1] <- glib
out[1,2:nc] <- pval
out