Hello Angel,
The problem below occurs because factored numbers are
ephemeral expressions. For example, if you factor 6 into the expression
2*3, Derive has to be very careful not to resimplify the expression 2*3 back to
6.
Version 6.10 of Derive does not resimplify factored
expressions when FACTOR is called at the top-level. The problem below occurs because the call on FACTOR is not
at the top-level. The next release of Derive will resolve the
problem. For example,
VECTOR(FACTOR(Rep(i), Number), i, 27,
27)
will simplify to [3^3 * 37 * 757 * 333667 *
440334654777631].
Note that unlike FACTOR, the vector of factors returned by
the FACTORS command is not ephemeral, and thus not susceptible to this
problem. Hope this explanation
helps.
Aloha,
Albert D. Rich
Co-author of Derive
----- Original Message -----
Sent: Tuesday, 01 February, 2005
06:22
Subject: Factorization not done
Hi Derive
users,
Defining Rep(n) := (10^n - 1)/9
VECTOR(FACTOR(Rep(i),
Number), i, 27, 27) =
[111111111111111111111111111]
but
FACTOR(Rep(27)) =
3^3·37·757·333667·440334654777631
Regards,
Angel
