Re: DiscreteUniformDistribution PDF isn't piecewise?

• To: mathgroup at smc.vnet.net
• Subject: [mg107696] Re: DiscreteUniformDistribution PDF isn't piecewise?
• From: Bill Rowe <readnews at sbcglobal.net>
• Date: Tue, 23 Feb 2010 08:03:50 -0500 (EST)

On 2/22/10 at 3:07 AM, nma at 12000.org (Nasser M. Abbasi) wrote:

>"richard.wesley.todd" <richard.wesley.todd at gmail.com> wrote in
>message news:hlqu3v\$go8\$1 at smc.vnet.net...
>>A PDF for a discrete uniform distribution, say for a die roll...

>>In[101]:= PDF[DiscreteUniformDistribution[{1, 6}]]

>>Out[101]= 1/6 &

>>... gives 1/6 for all inputs, _not_ just between 1 and 6.
>>Shouldn't it be defined piecewise?  This is from Mathematica
>>7.0.1.0 on Windows.   The CDF is correct.

>Not sure what you mean as you showed no example of the problem.

I believe what the original poster was doing is something like

In[5]:= f = PDF[DiscreteUniformDistribution[{1, 6}]];
f[10]

Out[6]= 1/6

Which is clearly the wrong result for 10. But, if f is defined as:

In[7]:= Clear[f];
f = PDF[DiscreteUniformDistribution[{1, 6}], #] &;
f[10]

Out[9]= 0