MathGroup Archive 2009

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

Search the Archive

Integrating InterpolatingFunction

  • To: mathgroup at smc.vnet.net
  • Subject: [mg105895] Integrating InterpolatingFunction
  • From: blamm64 <blamm64 at charter.net>
  • Date: Thu, 24 Dec 2009 00:14:50 -0500 (EST)

Man, how stupid am I?! (please don't answer that). My post just
previous to this ( I could not find a way to delete it and thereby not
suffer the shame of public humiliation) was full of errors, so I
apologize if you waded through it.

Several blunders in that post. In the definition of

xPfmodel[t_]=Integrate[fmodel[dp3p4],{s,0,t}];

dp3p4 = p3[t] - p4[t] was already set, so the definition should have
been

xPfmodel[t_]=Integrate[fmodel[p3[s]-p4[s]],{s,0,t}];

The definition xP2[t_]=Integrate[qFCnoT,{s,0,t}];

was stupid as well, it should have been

xP2[t_]=Integrate[qFCnoT /. t->s,{s,0,t}];

Which will give precisely the same result as

xP[t_]=Integrate[qFC[s],{s,0,t}] !

and I'm back where I started.  So, I am really stuck.

So my question is:

Given qFC[t_] = qFConIN[p3[t] - p4[t]] (which works fine), where
qFConIN is an InterpolatingFunction,

how can I get, effectively, something equivalent to

xP[t_]=Integrate[qFC[s],{s,0,t}] ?

-Brian L.


  • Prev by Date: Re: Re: NDSolve: Wrong Diagnosis as Delay Differential-Algebraic
  • Next by Date: Re: solving equations
  • Previous by thread: Re: complex numbers
  • Next by thread: Integration of Interpolation