q's about NumericQ and saving interpolating function

*To*: mathgroup at smc.vnet.net*Subject*: [mg46930] q's about NumericQ and saving interpolating function*From*: sean_incali at yahoo.com (sean kim)*Date*: Tue, 16 Mar 2004 02:37:40 -0500 (EST)*Sender*: owner-wri-mathgroup at wolfram.com

Hi steve, I think this message got lost. so here's another copy. hello group, i'm having problem understanding NumericQ. eq[a_?NumericQ] := y''[x] + a^2*y[x] == 0 sol[a_?NumericQ] := NDSolve[{eq[a], y[0] == 1, y'[0] == -1}, y, {x, 0, 10}] s1 = sol[4] Plot[y[x] /. s1, {x, 0., 10.}] question is, let's say some choices of "a" makes the equation non-numeric(ie, make the NDsolve fail), will the above expression evaluate? another and unrelated question is ... how do I export the interpolating function resulting from NDSolve routine? i remember seeing similar post in the group, but now I can't find it... the idea is to save the interpolating function as uniquely named files such that they can be recalled from the front end. thanks in advance again sean

**Follow-Ups**:**Physical Constants package***From:*Ed Pegg Jr <edp@wolfram.com>