Re: nested SetDelayed

*To*: mathgroup at smc.vnet.net*Subject*: [mg113378] Re: nested SetDelayed*From*: Bill Rowe <readnews at sbcglobal.net>*Date*: Tue, 26 Oct 2010 05:33:44 -0400 (EDT)

On 10/25/10 at 6:40 AM, kakabomba at gmail.com (O) wrote: >hello, maybe somebody can explain what i'm doing wrong in this >SIMPLE example: >In[1] := f[v_, k_] := Sin[v*k] >In[2] := test[v_] := NIntegrate[f[v, k], {k, 0, Pi}] >In[3] := FindRoot[test[x] == 1, {x, 1}] >I have NIntegrate errors: <error messages snipped> >Why expression `test` is evaluated with nonnumerical arguments?? >I guess my VisualBasic oriented brain can't understand how >SetDelayed work and how i should use it. The issue isn't the use of SetDelayed. Change the definition of test to be: test[v_?NumericQ] := NIntegrate[f[v, k], {k, 0, Pi}] and the error messages you saw will be eliminated.