Re: delayed function assignment
- To: mathgroup at smc.vnet.net
- Subject: [mg88201] Re: delayed function assignment
- From: leigh <leigh.pascoe at gmail.com>
- Date: Mon, 28 Apr 2008 04:38:41 -0400 (EDT)
- References: <fv1fec$eru$1@smc.vnet.net>
On Apr 27, 11:02 am, leigh <leigh.pas... at gmail.com> wrote: > Dear Mathgroup, > > I am trying to integrate the pdf of a chi-square mixture distribution. > If I define the pdf as > > pdf2[0] := .25 > \!\(pdf2[x] := .5*\(\(1/2\^\(1/ > 2\)\)\/Gamma[1/2]\) \(x\^\(1/2 - 1\)\) \[ExponentialE]\^\(\(-x > \)/ > 2\) + .25*\(1\/\(2*Gamma[1]\)\) \[ExponentialE]\^\(\(-x > \)/2\)\) > > I can then obtaing the cumulative distribution function symbolically > as > > In[14]:=\!\($B"i(Bpdf2[x] \[DifferentialD]x\) > > Out[14]=\!\(\(-0.25`\)\ 2.718281828459045`\^\(\(-0.5`\)\ x\) + 0.5`\ \ > Erf[0.7071067811865476`\ \@x]\) > > I can get numerical values using for example > > In[31]:=\!\(1 - .25 - $B"i(B\_0\%12 pdf2[x] \[DifferentialD]x\) > > Out[31]=0.000885691 > > However if I try to define this as a function of the statistic > obtained, say > > \!\(cum2[x] := 1 - .25 - $B"i(B\_0\%x pdf2[t] \[DifferentialD]t\) > > Then > > In[33]:=cum2[9] > > Out[33]=cum2[9] > > Doesn't evaluate. What should I do to obtain the value as output. > > Thanks for your help > > Leigh Oops, I guess it is a while since I have used Mathematica and I foolishly thought I remembered the correct syntax for a delayed function assignment. Thank you to those who replied to my post and for the suggestions. Leigh