Services & Resources / Wolfram Forums
MathGroup Archive
*Archive Index
*Ask about this page
*Print this page
*Give us feedback
*Sign up for the Wolfram Insider

MathGroup Archive 2006

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

Search the Archive

Errors at discontinuities

  • To: mathgroup at
  • Subject: [mg65110] Errors at discontinuities
  • From: "Narasimham" <mathma18 at>
  • Date: Wed, 15 Mar 2006 06:28:22 -0500 (EST)
  • Sender: owner-wri-mathgroup at

Errors appear at start / period cross-over points of  a triangular wave
on t-axis  with  period a, amplitude b. Why does not
Plot[  D[fn[t,3,4],t]  / D[fn[t,5,5.65],t] , {t, 0,tmax}] ; Or
Plot[  D[fn[t,3,4],t]  , {t, 0,tmax}] ;
work at beginning when the same works erroneously later on in sl1 and
gets self-corrected  at sl2? And how to remedy the situation?  TIA

a= 4 ; b = 3 ; tmax=10;
fn[u_,lam_,A_]=A*ArcSin[Sin[ 2 Pi u/lam]]*2/Pi ;
Plot[ fn[t,a,b], {t, 0,tmax}] ;
Plot[  D[fn[t,a,b],t]  / D[fn[t,c,d],t] , {t, 0,tmax}] ;
sl1=D[fn[t,a,b],t]/D[fn[t,c,d] ] ; Plot[ sl1 ,  {t, 0, tmax}] ;
sl2= D[fn[t,a,b],t]/D[fn[t,c,d],t] ; Plot [sl2, {t, 0, tmax}] ;

  • Prev by Date: Re: Sorting Rows of a Matrix
  • Next by Date: Re: Factoring
  • Previous by thread: Re: ScatterPlot3D with One More Dimension?
  • Next by thread: Re: Errors at discontinuities