RE: what's wrong about my package?
- To: mathgroup at smc.vnet.net
- Subject: [mg45424] RE: [mg45391] what's wrong about my package?
- From: "David Park" <djmp at earthlink.net>
- Date: Wed, 7 Jan 2004 01:09:17 -0500 (EST)
- Sender: owner-wri-mathgroup at wolfram.com
Andy,
In your last statement
BernsteinPolynomial[fx_, x_,n_] :=Module[{},Sum[Replace[fx,
x ->i/n]*Bernstein[i, n, t], {i, 0, n}]];
you introduced the symbol t and since this is introduced in the Private
section of your package it has the complete domain specification of
CAGD`Private`t
and that is what you are complaining about. But I have no idea what should
be there instead of t. If t is supposed to be a variable that is used in the
answer, you may want to replace the last call with
Bernstein[i, n, Global`t]
But it might be better to let the user pass the symbol he wishes to use.
David Park
djmp at earthlink.net
http://home.earthlink.net/~djmp/
From: ANDY [mailto:wangzhengyao at hotmail.com]
To: mathgroup at smc.vnet.net
hello,
i want to build a package about computer aided Geometirc design for me!
____________________________________
......
Begin["`Private`"]
Bernstein[i_, n_, v_] := Binomial[n, i]*(1 - v)^(n - i)*v^i
BezierCurve[pts : {{_, _} ..} | {{_, _, _} ..}, v_] :=
Module[{n = Length[pts] - 1},
Simplify[
Table[Bernstein[i, n, v], {i, 0, n}].pts]
];
BernsteinPolynomial[fx_, x_,n_] :=Module[{},Sum[Replace[fx,
x ->i/n]*Bernstein[i, n, t], {i, 0, n}]];
End[]
EndPackage[]
___________________________________
i want use BernsteinPolynomial to compute the Bernstein Polynomial of the
function fx (f(x)),but when i use it in mathematica,there are something
wrong:
In[28]:=
\!\(BernsteinPolynomial[x\^2 + x, x, 8]\)
Out[28]=
\!\(\((1 - CAGD`Private`t)\)\^8\ \((x + x\^2)\) + 8\ \((1 -
CAGD`Private`t)\)\
\^7\ CAGD`Private`t\ \((x + x\^2)\) + 28\ \((1 - CAGD`Private`t)\)\^6\ \
CAGD`Private`t\^2\ \((x + x\^2)\) + 56\ \((1 - CAGD`Private`t)\)\^5\ \
CAGD`Private`t\^3\ \((x + x\^2)\) + 70\ \((1 - CAGD`Private`t)\)\^4\ \
CAGD`Private`t\^4\ \((x + x\^2)\) + 56\ \((1 - CAGD`Private`t)\)\^3\ \
CAGD`Private`t\^5\ \((x + x\^2)\) + 28\ \((1 - CAGD`Private`t)\)\^2\ \
CAGD`Private`t\^6\ \((x + x\^2)\) + 8\ \((1 - CAGD`Private`t)\)\ \
CAGD`Private`t\^7\ \((x + x\^2)\) + CAGD`Private`t\^8\ \((x + x\^2)\)\)
Why?
how to correct it??
thank you?
Andy
2004.1.5