Re: Taking the Log causing Mathematica kernel crash.

*To*: mathgroup at smc.vnet.net*Subject*: [mg57055] Re: [mg57051] Taking the Log causing Mathematica kernel crash.*From*: zhengji.li at t3gt.com*Date*: Fri, 13 May 2005 01:18:49 -0400 (EDT)*Sender*: owner-wri-mathgroup at wolfram.com

You may have made some mistakes. Maybe you mean this(it works well): Clear["Global`*"] f[t_] := Sin[3.5 t] + 2 Cos[2 t]; g[t_] := Piecewise[{{0, t < -2Pi}, {f[t], t >= -2Pi && t <= 2Pi}, {0, t > 2Pi}}]; c[w_] = Integrate[g[t] Exp[-I w t], {t, -Infinity, Infinity}]; (* Fourier Transform*) Plot[20 Log[10, Abs[c[w]]], {w, -5, 5}, PlotRange -> All] 1. The definition of g[t] is wrong. 2. c[w_] = ... but not c[w_] := ... "me" <nma at 12000.org> To: mathgroup at smc.vnet.net cc: 05, 13, 2005 Subject: [mg57055] [mg57051] Taking the Log causing Mathematica kernel crash. 10:44 AM Please respond to "me" Mathematica 5.1 on Windows. Clear["Global`*"] f[t_] := Sin[3.5 t] + 2 Cos[2 t]; g[t_] := Piecewise[{{0, t < -2Pi}, { f[t], t = -2Pi && t = 2Pi}, {0, t > 2Pi}}]; c[w_] := Integrate[ g[t] Exp[-I w t], {t, -Infinity, Infinity}] ; Plot[20 Log[10, Abs[c[w]]], {w, -5, 5}, PlotRange -> All] The above code causes Mathemtica kernel crash. Change the last line above to remove the Log, then it is OK: Plot[20 Abs[c[w]], {w, -5, 5}, PlotRange -> All] Nasser