MathGroup Archive 2009

[Date Index] [Thread Index] [Author Index]

Search the Archive

Re: question

  • To: mathgroup at smc.vnet.net
  • Subject: [mg105690] Re: question
  • From: Peter Pein <petsie at dordos.net>
  • Date: Tue, 15 Dec 2009 07:28:35 -0500 (EST)
  • References: <hg4h25$gfu$1@smc.vnet.net>

Am 14.12.2009 06:05, schrieb Piotr Munik:
> I have a problem with BSpline Function.
> I want to know how can I make derivative of BSplineFunction.
> Example
> I have date:
> A = {{35460.`, 3679.0872`}, {35460.69264747737`,
>   3687.7503846982163`}, {35461.28773994215`,
...
>   3721.3768697843334`}, {35479.201331936965`, 3726.7002787009123`}};
> and I have a BSplineFunction:
> In[1] fn = BSplineFunction[A, SplineDegree -> 3]
> Out[1] BSplineFunction[{{0.,1.}},<>]
> I need derivative of function from Out[1]
> Thank You
> Piotr
> 
> 

Assuming you want the derivative of fn[[2]] with respect to fn[[1]], I
would use

dfn[t_]:={First[fn[t]],Divide@@Reverse[fn'[t]]}

and

ParametricPlot[f1[x], {x, 0, 1}, AspectRatio -> 1/GoldenRatio]

looks OK to me.

Peter


  • Prev by Date: Re: Buying and running older version of Mathematica on a Netbook
  • Next by Date: Re: would like to compute a tensor derivative of a function and
  • Previous by thread: Re: question
  • Next by thread: Re: question