delayed function assignment

*To*: mathgroup at smc.vnet.net*Subject*: [mg88170] delayed function assignment*From*: leigh <leigh.pascoe at gmail.com>*Date*: Sun, 27 Apr 2008 04:57:43 -0400 (EDT)

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

**Follow-Ups**:**Re: delayed function assignment***From:*"W_Craig Carter" <ccarter@mit.edu>