CODEWITHSUNDEEP
rif-statementfor-loop
cwalter
cwalter

Reputation: 21

for loop creating vector r

I am trying to create a function to calculate the Box-Cox transformation in R, where you iterate values of lambda (lambdas) in a formula to maximize L. What I ultimately want is a vector of L, such that for all i in lambda, there is a corresponding L value.

y <- c(256,256,231,101,256,213,241,246,207,143,287,240,262,234,146,255,184,161,252,229,283,132,218,113,194,237,181,262,104)
df <- 28
n=29
lambdas <- seq(-3,3,0.001)
L <- c(rep(NA,length(lambdas)))


for(i in lambdas) {
if(i != 0) {
yprime <- (((y^i)-1)/i)
} else 
{   yprime <- log(y)
}
st2 <- var(yprime)
L <- (((-df/2)*(log(st2))) + ((i-1)*(df/n)*(sum(log(y)))))
}

What I typically end up with L as a vector of 1, with the final iteration calculated.

Upvotes: 1

Views: 896

Answers (1)

IRTFM
IRTFM

Reputation: 263311

Use seq_along to generate an index for lambdas[] and L[]

for(i in seq_along(lambdas)) {
   if(i != 0) {
     yprime <- (((y^lambdas[i])-1)/lambdas[i])
     } else { 
     yprime <- log(y)
              }
   st2 <- var(yprime)
   L[i] <- (((-df/2)*(log(st2))) + ((lambdas[i]-1)*(df/n)*(sum(log(y)))))
 }
plot(L)

Upvotes: 1

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