Cannot set attributes on NULL

[justinkamerman]

Hi Justin,

I am trying to help my other student debug some of her code and at one point she calls p.QFASA so that she can use the result as a starting vector in her optimization algorithm. When I called the p.QFASA function, however, I got this warning:

Warning message:
In structure(c(), class = c(class(x), class(y))) :
  Calling 'structure(NULL, *)' is deprecated, as NULL cannot have attributes.
  Consider 'structure(list(), *)' instead.

Because she just needs starting values which appear to be correct, she was not overly concerned and has been ignoring the warnings. At first, I assumed she was doing something different but finally was able to pinpoint where the warning was coming from and I think it’s a result of a new change in R. The warning comes from AIT.obj and specifically in the line:

sealhat <- t(as.matrix(alpha)) %*% prey.quantiles

(I’m guessing the warning would also happen using the other distance measures.)

According to R news:

structure(NULL, ..) is now deprecated as you cannot set attributes on NULL.

So my worry is that users of QFASA will now get this warning message. (When I tried to run the line above on some old data, I also got this message.)

Anyways, I don’t want you to spend a lot of time on this but if you think this is an issue with an easy fix – feel free to look into it!

Thanks!!

Connie