Re: NIntegrate a list

*To*: mathgroup at smc.vnet.net*Subject*: [mg52986] Re: NIntegrate a list*From*: Bill Rowe <readnewsciv at earthlink.net>*Date*: Sat, 18 Dec 2004 04:00:32 -0500 (EST)*Sender*: owner-wri-mathgroup at wolfram.com

On 12/17/04 at 5:19 AM, aaronfude at yahoo.com (Aaron Fude) wrote: >I can Integrate this, but apparently not NIntegrate this: >Integrate[x*Sin[x]*{1, 2}, {theta, -Pi, Pi}] >but not >NIntegrate[x*Sin[x]*{1, 2}, {theta, -Pi, Pi}] >Is there a good way to do this (w/o writing loops)? Did you mean to write Integrate[x*Sin[x]*{1, 2}, {x, -Pi, Pi}] instead of what you did write? Since Integrate returns a symbolic answer, it is reasonable to expect Integrate to work. But NIntegrate is a numerical integration routine. As you wrote it, there is no way for Mathematica to assign a number to x and the numerical integration fails. There is also a second issue in that NIntegrate does not have the attribute Listable. But this can be addressed using Map, i.e. NIntegrate[#1, {x, -Pi, Pi}]&/@ (x Sin[x] {1, 2}) {6.283185307179588, 12.566370614359176} -- To reply via email subtract one hundred and four