RE: Interpolating function
- To: mathgroup at smc.vnet.net
- Subject: [mg9835] RE: [mg9737] Interpolating function
- From: Ersek_Ted%PAX1A at mr.nawcad.navy.mil
- Date: Fri, 28 Nov 1997 05:35:47 -0500
- Sender: owner-wri-mathgroup at wolfram.com
jmthomas wrote:
|--------------------------------------------- | Interpolation[data]
| comes with an option InterpolationOrder, which by default is set to |
Three, meaning it guarantees the continuity of the interpolation |
function for the first and second derivative. |
I replied with:
|
|That's what I used to think Interpolation did, but consider the example
below.
|In Out[3] you get a plot of the Interpolation, and you will |see it is
continuous (good).
|In Out[4] you get a plot of the 2nd derivative of the interpolation,
and you will
|see it is piecewise linear, but not continuous. | (* See my
previous post for the details of the example. *) |
jmthomas replied with:
To me, the second derivative of "inter" IS continuous (no gaps between
two very close points), and is piecewise linear. The third derivative
is not continuous, and piecewise constant.
----------------------------------------------
After taking another look it seems you are right. I don't know what I
was thinking to conclude otherwise.
----------------------------------------------- Also:
In hind site I feel like a fool for my other recent post, "Want to use
Module".
The solution to my problem is simply:
In[1]:=
y[x_]:=x*Exp[x]+2;
In[2]:=
foo[x_]:=With[{temp=y[x]},
2/(3+temp)/;temp<100]
I just assumed the Kernal wasn't flexible enough to have a condition for
foo[x_]:=(.......) inside With[.......]. I guess I should have tried
it instead of assuming it wouldn't work.
Ted Ersek
ersek_ted%pax1a at mr.nawcad.navy.mil