Re: StruveH runtime error

*To*: mathgroup at smc.vnet.net*Subject*: [mg45679] Re: StruveH runtime error*From*: "Alan" <infoNOSPAM at optioncity.net>*Date*: Mon, 19 Jan 2004 05:15:22 -0500 (EST)*References*: <buap11$mim$1@smc.vnet.net>*Sender*: owner-wri-mathgroup at wolfram.com

> I am having troubles in evaluating StruveH functions. > > StruveH[1,10^4]=0.643716 > took 278356 sec on P4, 2.8GHz (HDD 120GB, 1024MB PC3200 RAM) Win XP SP1 > machine with Mathematica v.5.0. > It took really long time. But the value could be evaluated. > > However, > StruveH[1,10^5] > could not be evaluated, because the session was terminated with a Windows > error message Abramowitz & Stegun says: StruveH[1, z] ~ BesselY[1,z] + (2/Pi)(1 + 1/z^2 - 3/z^4 + 45/z^6 + O(1/z^8)) Let h[z] = BesselY[1,z] + (2/Pi)(1 + 1/z^2 - 3/z^4 + 45/z^6) In[123]:= Timing[N[h[10^4]]] Out[123]= {0.016 Second, 0.643716} In[122]:= Timing[N[h[10^5]]] Out[122]= {0. Second,0.638339} Regards, alan