Re: why doesn't the range on this interval match the plot range?

*To*: mathgroup at smc.vnet.net*Subject*: [mg66440] Re: [mg66394] why doesn't the range on this interval match the plot range?*From*: Bruce Miller <brucem at wolfram.com>*Date*: Fri, 12 May 2006 02:03:46 -0400 (EDT)*References*: <200605110615.CAA17227@smc.vnet.net>*Sender*: owner-wri-mathgroup at wolfram.com

On May 11, 2006, at 1:15 AM, Chris Chiasson wrote: > Parabola[x_]=4x^2+53x+160 > BeginPoint=-8; > EndPoint=-5; > Plot[Parabola[x],{x,BeginPoint,EndPoint}] > Parabola[Interval[{BeginPoint,EndPoint}]] > > -- > http://chris.chiasson.name/ > Interval is not set up for multi-level arithmetic, since the second level treats the Intervals as independent. For example, in the Trace below note that Interval[{100,256}] is reversed (-8 end and -5 ends switched) compared with the Interval for the linear term. (This is with version 5.2.) In[4]:= ibe=Interval[{BeginPoint,EndPoint}] Out[4]= Interval[{-8, -5}] In[5]:= Parabola[ibe] Out[5]= Interval[{-164, 151}] In[6]:= Trace[ Parabola[ibe] ] Out[6]= {{ibe, Interval[{-8, -5}]}, Parabola[Interval[{-8, -5}]], 2 160 + 53 Interval[{-8, -5}] + 4 Interval[{-8, -5}] , {53 Interval[{-8, -5}], Interval[{-424, -265}]}, 2 {{Interval[{-8, -5}] , Interval[{25, 64}]}, 4 Interval[{25, 64}], Interval[{100, 256}]}, 160 + Interval[{-424, -265}] + Interval[{100, 256}], Interval[{-164, 151}]} I did not find a simple workaround. I will ask about clarifying the documentation on what arithmetic can be done with Interval[list]. Bruce Miller Technical Support Wolfram Research, Inc. support at wolfram.com http://support.wolfram.com/

**References**:**why doesn't the range on this interval match the plot range?***From:*"Chris Chiasson" <chris@chiasson.name>