Re: on a pure function for a list of integrals

*To*: mathgroup at smc.vnet.net*Subject*: [mg77333] Re: on a pure function for a list of integrals*From*: "Jean-Marc Gulliet" <jeanmarc.gulliet at gmail.com>*Date*: Thu, 7 Jun 2007 03:38:57 -0400 (EDT)*References*: <f43gpj$2k7$1@smc.vnet.net> <4665D6FB.9070505@gmail.com>

On 6/6/07, Ruth <ruth.lazkoz at ehu.es> wrote: > Thanks, Jean-Marc, you suggest > > f = Block[{x, a = #1, b = #2}, > (NIntegrate[Sqrt[a*x + b], {x, 0, #1}] & ) /@ #3] & ; > f[2, 3, {0.1, 0.5, 0.9}] > > but I think there are assignments which are never used as > > In[1]:= f = Block[{x}, > (NIntegrate[Sqrt[a*x + b], {x, 0, #1}] & ) /@ #3] & ; > f[2, 3, {0.1, 0.5, 0.9}] > > gives me exactly the same result so the bit a = #1, b = #2 seems unnecessary How much do you bet on that :-) In[1]:= f = Block[{x}, (NIntegrate[Sqrt[a*x + b], {x, 0, #1}] & ) /@ #3] & ; f[2, 3, {0.1, 0.5, 0.9}] During evaluation of In[1]:= NIntegrate::inumr:The integrand Sqrt[b+a \ x] has evaluated to non-numerical values for all sampling points in \ the region with boundaries {{0,0.1}}. >> During evaluation of In[1]:= NIntegrate::inumr:The integrand Sqrt[b+a \ x] has evaluated to non-numerical values for all sampling points in \ the region with boundaries {{0,0.5}}. >> During evaluation of In[1]:= NIntegrate::inumr:The integrand Sqrt[b+a \ x] has evaluated to non-numerical values for all sampling points in \ the region with boundaries {{0,0.9}}. >> During evaluation of In[1]:= General::stop:Further output of \ NIntegrate::inumr will be suppressed during this calculation. >> Out[2]= {NIntegrate[Sqrt[a*x + b], {x, 0, 0.1}], NIntegrate[Sqrt[a*x + b], {x, 0, 0.5}], NIntegrate[Sqrt[a*x + b], {x, 0, 0.9}]} Regards, Jean-Marc