RE: ? ? ? ! ?
- To: mathgroup at smc.vnet.net
- Subject: [mg8320] RE: [mg8223] ? ? ? ! ?
- From: "Richard W. Finley, M. D." <trfin at umsmed.edu>
- Date: Sun, 24 Aug 1997 13:24:35 -0400
- Sender: owner-wri-mathgroup at wolfram.com
Lou,
I guess it thinks it is plotting the derivative of the absolute value =
function, but it obviously doesn't know how to differentiate this =
function correctly. The derivative should be a step function and should =
exist everywhere except x=3D0, so it isn't clear to me what algorithm is =
being used here that fails. Perhaps someone from Wolfram will enlighten =
us...??
RF
-----Original Message-----
From: Lou Talman [SMTP:me at talmanl.mscd.edu]
To: mathgroup at smc.vnet.net
Sent: Tuesday, August 19, 1997 8:12 PM
To: mathgroup at smc.vnet.net
Subject: [mg8223] ? ? ? ! ?
Can anyone explain what v3.0 of Mathematica thinks it's doing when it
executes
Plot[Abs'[x], {x, -3/10, 3/10}]
???
Note the prime: The first argument of Plot was Abs'[x], not Abs[x].
The strange behavior I see appears both on a PowerMac 7200/120 running
Mac OS 7.5.3 and on a Wintel box running Windoze 95, so I presume that=20
it isn't platform dependent--or at least, not fully so.
--Lou Talman