Re: Constructing Expressions from List Elements

*To*: mathgroup at smc.vnet.net*Subject*: [mg2207] Re: Constructing Expressions from List Elements*From*: ianc (Ian Collier)*Date*: Mon, 16 Oct 1995 11:53:15 -0400*Organization*: Wolfram Research, Inc.

In article <44t3p9$6t5 at ralph.vnet.net>, brianb at dendrite.cs.colorado.edu (Brian Bonnlander) wrote: > I have a list of integration limits that I would like to incorporate into > an NIntegrate[] expression. I don't know the proper syntax for accomplishing > this. > > For example, I would like to integrate f[x,y,z] where the integration limits > are contained in a list *limits*, expressed perhaps as > limits = {{x, 0, 1}, {y, -Infinity, Infinity}, {z, 0, 1}}. > > The statement I would like to construct is > > NIntegrate[f[x,y,z], {x, 0, 1}, {y, -Infinity, Infinity}, {z, 0, 1}] . > > > How do I remove the outer list braces for *limits* so that I can construct > this statement? > > > Thanks in advance, > > --Brian You can substitute your own function for Sin[ x y z] in the following: In[12]:= limits = {{x, 0, 1}, {y, -Infinity, Infinity}, {z, 0, 1}} Out[12]= {{x, 0, 1}, {y, -Infinity, Infinity}, {z, 0, 1}} In[13]:= Prepend[ limits, Sin[x y z] ] Out[13]= {Sin[x y z], {x, 0, 1}, {y, -Infinity, Infinity}, {z, 0, 1}} In[14]:= Apply[ NIntegrate, %] Out[14]= 1429 -4.89109 10 Alternativesare : NIntegrate[Sin[x y z], ##]& @@ limits NIntegrate[Sin[x y z], Sequence @@ limits] I hope this helps. --Ian ----------------------------------------------------------- Ian Collier Technical Sales Support Wolfram Research, Inc. ----------------------------------------------------------- tel:(217)-398-0700 fax:(217)-398-0747 ianc at wri.com Wolfram Research Home Page: http://www.wri.com/ -----------------------------------------------------------