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Re: Inverse CDF of standard normal is (according to Maple 15) complex valued for some positive inputs!

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From Joe Riel <joer@san.rr.com>
Newsgroups comp.soft-sys.math.maple
Subject Re: Inverse CDF of standard normal is (according to Maple 15) complex valued for some positive inputs!
Date Mon, 05 Dec 2011 12:51:15 -0800
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jdm <james.d.mclaughlin@gmail.com> writes:

> Thanks! Do you know how I can get this to work with plot? When I try
>
>> plot(f2(2^(-a)), a = 1 .. 56);
>
> I get "Error, (in fsolve) a is in the equation, and is not solved
> for".

Try plot('f2(2^(-a))', a=1..56);

I see, though, that there is a better solution on MaplePrimes.


>
> James.
>
>> Try the following,
>>
>> with(Statistics):
>> Phiinverse := (x) -> Quantile(Normal(0, 1), x):
>>
>> f1 := Phiinverse(x);
>>                                                        1/2
>>                      f1 := RootOf(-erf(_Z) - 1 + 2 x) 2
>>
>> f2 := subsindets(f1
>>                  , 'specfunc(anything,RootOf)'
>>                  , rootof -> unapply('fsolve'(op(rootof), _Z), x)
>>                 );
>>                                                             1/2
>>                f2 := (x -> fsolve(-erf(_Z) - 1 + 2 x, _Z)) 2
>>
>> evalf(f2(1-1/2^24));
>>                                   5.294704084
>>
>> --
>> Joe Riel
>

-- 
Joe Riel

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Thread

Inverse CDF of standard normal is (according to Maple 15) complex valued for some positive inputs! jdm <james.d.mclaughlin@gmail.com> - 2011-12-05 09:09 -0800
  Re: Inverse CDF of standard normal is (according to Maple 15) complex valued for some positive inputs! Joe Riel <joer@san.rr.com> - 2011-12-05 10:18 -0800
    Re: Inverse CDF of standard normal is (according to Maple 15) complex valued for some positive inputs! jdm <james.d.mclaughlin@gmail.com> - 2011-12-05 12:08 -0800
      Re: Inverse CDF of standard normal is (according to Maple 15) complex valued for some positive inputs! Joe Riel <joer@san.rr.com> - 2011-12-05 12:51 -0800
        Re: Inverse CDF of standard normal is (according to Maple 15) complex valued for some positive inputs! jdm <james.d.mclaughlin@gmail.com> - 2011-12-05 13:28 -0800
          Re: Inverse CDF of standard normal is (according to Maple 15) complex valued for some positive inputs! jdm <james.d.mclaughlin@gmail.com> - 2011-12-05 13:46 -0800
            Re: Inverse CDF of standard normal is (according to Maple 15) complex valued for some positive inputs! jdm <james.d.mclaughlin@gmail.com> - 2011-12-05 14:43 -0800
              Re: Inverse CDF of standard normal is (according to Maple 15) complex valued for some positive inputs! Joe Riel <joer@san.rr.com> - 2011-12-05 15:32 -0800
                Re: Inverse CDF of standard normal is (according to Maple 15) complex valued for some positive inputs! jdm <james.d.mclaughlin@gmail.com> - 2011-12-05 16:04 -0800
                Re: Inverse CDF of standard normal is (according to Maple 15) complex valued for some positive inputs! Herman Rubin <hrubin@skew.stat.purdue.edu> - 2011-12-07 02:06 +0000

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