LinearRecurrence syntax
- To: mathgroup at smc.vnet.net
- Subject: [mg115939] LinearRecurrence syntax
- From: "Mr. Wizard" <gleam at flashmail.com>
- Date: Wed, 26 Jan 2011 05:07:14 -0500 (EST)
It seems to me that the syntax for LinearRecurrence is not in
agreement with other Mathematica functions.
In:= LinearRecurrence[{1, 1}, {1, 1}, {10}]
Out= {1, 1, 2, 3, 5, 8, 13, 21, 34, 55}
I expected 55 or {55}. One must enter 10 twice:
In:= LinearRecurrence[{1, 1}, {1, 1}, {10,10}]
Out= {55}
Contrast this with:
Take[Range@5, {3}]
Ordering[Range@10, {5}]
StringTake["abcdefg", {3}]
IntegerPartitions[5, {3}]
Subsets[Range@4, {3}]
Permutations[Range@3, {2}]
In none of these cases must one enter the index twice.
Further, the functions that take a Levelspec, read {x} as the
specific level x, not one through x. Again, one does not have to enter {x, x}.
a = Array[Plus, {4, 5}];
Total[a, {2}]
Map[EvenQ, a, {2}]
Perhaps I am overlooking something obvious, but it seems to me that
the behavior of LinearRecurrence[list, list, {i}] should be changed
from "one through i" to only "i."
Paul