Re: NIntegrate with variable region

*To*: mathgroup at smc.vnet.net*Subject*: [mg6287] Re: [mg6254] NIntegrate with variable region*From*: Paul Abbott <paul at physics.uwa.edu.au>*Date*: Sat, 8 Mar 1997 00:26:07 -0500 (EST)*Organization*: University of Western Australia*Sender*: owner-wri-mathgroup at wolfram.com

Zvi Wiener wrote: > I wish to take an indefinite integral of a piecewise > continuous function. For example: > > f[x_]:= Which[ x<0, 0, x<1, 1, x>=1, x]; > > I tried: > lst = {-1,0,1,2}; > NIntegrate[ f[x], Prepend[lst,x]] > > But the result was: > > NIntegrate::vars: > Integration range specification Prepend[lst, x] > is not of the form {x, xmin, ..., xmax}. > > NIntegrate[f[x], Prepend[lst, x]] Prepend[lst,x] is not evaluated because In[3]:= Attributes[NIntegrate] Out[3]= {HoldAll,Protected} You need to evaluate the Integration range: In[4]:= NIntegrate[ f[x], Evaluate[Prepend[lst,x]]] Out[4]= 2.5 Cheers, Paul _________________________________________________________________ Paul Abbott Department of Physics Phone: +61-9-380-2734 The University of Western Australia Fax: +61-9-380-1014 Nedlands WA 6907 paul at physics.uwa.edu.au AUSTRALIA http://www.pd.uwa.edu.au/Paul God IS a weakly left-handed dice player _________________________________________________________________