Even if I copy the example from here: http://www.gnu.org/software/emacs/manual/html_node/calc/Linear-Fits.html#Linear-Fits this one:
[ [ 1, 2, 3, 4, 5 ] [ 5, 7, 9, 11, 13 ] ]
to be more specific, and then press a F 1 RET, all I get is the error message "Model expression is too complex: a + b * x". Do I have to do something special to make it work? Calc can plot data, so that's not an issue.
emacs -Q gives the same result.
GNU Emacs 24.3.1 (x86_64-redhat-linux-gnu, GTK+ Version 3.8.2) of 2013-08-14 on buildvm-15.phx2.fedoraproject.org