If lattice in function - r

Question

I am trying to create a function that returns different values when the variable is in different ranges.
nhpp_lambda <- function(t) {
for (t in 1:365) {
if (t >= "1" && t <= "59")
lambda = 20.83
else if (t >= "60" && t <= "151")
lambda = 11.02
else if (t >= "152" && t <= "243")
lambda = 11.68
else if (t >= "244" && t <= "334")
lambda = 26.41
else if (t >= "335" && t <= "365")
lambda = 20.83
}
return(lambda)
}
how come this doesn't work? it still just always returns 20.83??

Answer 1

In the function you have defined you return the value of lambda after the loop has finished, and in the last iteration of the loop, the value is always 20.83. If you remove the loop, it will work, e.g.,
nhpp_lambda <- function (t) {
if (t >= 1 && t <= 59)
lambda = 20.83
else if (t >= 60 && t <= 151)
lambda = 11.02
else if (t >= 152 && t <= 243)
lambda = 11.68
else if (t >= 244 && t <= 334)
lambda = 26.41
else if (t >= 335 && t <= 365)
lambda = 20.83
return(lambda)
}
nhpp_lambda(5)
nhpp_lambda(55)
nhpp_lambda(120)
nhpp_lambda(285)
nhpp_lambda(340)

Answer 2

Firstly, you're taking $t$ as a function argument, but then defining $t$ through the loop $1:365$, so that $t$ cycles in values from $1,2,\dots,365$. Remove the for() loop, it serves no purpose.
Secondly, you're comparing a number $t$ to strings "1","59",etc. Remove the quoations, you should be comparing $t$ to integers not characters/strings. Here is the correct code
nhpp_lambda <- function(t) {
if (t >= 1 && t <= 59)
lambda = 20.83
else if (t >= 60 && t <= 151)
lambda = 11.02
else if (t >= 152 && t <= 243)
lambda = 11.68
else if (t >= 244 && t <= 334)
lambda = 26.41
else if (t >= 335 && t <= 365)
lambda = 20.83
return(lambda)
}