initial-frame-alist's value is nil

Documentation:
*Alist of frame parameters for creating the initial X window frame.
You can set this in your `.emacs' file; for example,
 (setq initial-frame-alist '((top . 1) (left . 1) (width . 80) (height . 55)))
Parameters specified here supersede the values given in `default-frame-alist'.

If the value calls for a frame without a minibuffer, and you have not created
a minibuffer frame on your own, one is created according to
`minibuffer-frame-alist'.

You can specify geometry-related options for just the initial frame
by setting this variable in your `.emacs' file; however, they won't
take effect until Emacs reads `.emacs', which happens after first creating
the frame.  If you want the frame to have the proper geometry as soon
as it appears, you need to use this three-step process:
* Specify X resources to give the geometry you want.
* Set `default-frame-alist' to override these options so that they
  don't affect subsequent frames.
* Set `initial-frame-alist' in a way that matches the X resources,
  to override what you put in `default-frame-alist'.

You can customize this variable.

Defined in `frame'.