Re: Unevaluated functions
- To: mathgroup at smc.vnet.net
- Subject: [mg109350] Re: Unevaluated functions
- From: mokambo <alexandrepassosalmeida at gmail.com>
- Date: Fri, 23 Apr 2010 03:47:23 -0400 (EDT)
- References: <hqou0u$9g5$1@smc.vnet.net> <hqp995$gqv$1@smc.vnet.net>
Thanks Albert and Bob,
To give an example, the multiplicative inverse of 3 computed with
PowerMod[3, -1, 288]
does not evaluate and prints the message:
PowerMod::ninv:3 is not invertible modulo 288
Following your suggestions I tried:
PowerMod[___] := "N/A";
but it does not work unless you unprotect the symbol (a bad idea)
Attributes[PowerMod]
= {Listable, Protected, ReadProtected}
So I searched through the docs and found:
Check[PowerMod[3, -1, 288], "N/A"]
which still prints the error message (can be suppressed with Quiet)
but "returns" N/A as desired :)
Thanks!