New user: Custom probability distribution

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New user: Custom probability distribution

Jan Danielsson
Hello,

   Given a probability function: p(x) = 12 / (25(x+1)) , x=0, 1, 2, 3 we
generate the following values:

  C1  C2
  0   0.48
  1   0.24
  2   0.16
  3   0.12

   Now, I'm supposed to create 50 random values using this table. In
MiniTab, I simply selected Calc -> Random Data -> Discrete, and selected
the columns, and it created 50 random values in a new column.[1]

How do I do the same thing in R?

   [1] You may be wondering why I'm telling you this. Well, it's because
if I were in your shoes, I'd think "Oh, someone wants me to solve his
homework.". I have already solved it using MiniTab, but I want to be
able to use R instead (since I prefer NetBSD).

--
Kind Regards,
Jan Danielsson
Te audire non possum. Musa sapientum fixa est in aure.


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Re: New user: Custom probability distribution

tom wright-3
rbinom(50,5,c(0.48,0.24,0.16,0.12))


On Thu, 2006-09-02 at 20:02 +0100, Jan Danielsson wrote:

> Hello,
>
>    Given a probability function: p(x) = 12 / (25(x+1)) , x=0, 1, 2, 3 we
> generate the following values:
>
>   C1  C2
>   0   0.48
>   1   0.24
>   2   0.16
>   3   0.12
>
>    Now, I'm supposed to create 50 random values using this table. In
> MiniTab, I simply selected Calc -> Random Data -> Discrete, and selected
> the columns, and it created 50 random values in a new column.[1]
>
> How do I do the same thing in R?
>
>    [1] You may be wondering why I'm telling you this. Well, it's because
> if I were in your shoes, I'd think "Oh, someone wants me to solve his
> homework.". I have already solved it using MiniTab, but I want to be
> able to use R instead (since I prefer NetBSD).
>
> ______________________________________________
> [hidden email] mailing list
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html

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Re: New user: Custom probability distribution

Duncan Murdoch
In reply to this post by Jan Danielsson
On 2/9/2006 2:02 PM, Jan Danielsson wrote:

> Hello,
>
>    Given a probability function: p(x) = 12 / (25(x+1)) , x=0, 1, 2, 3 we
> generate the following values:
>
>   C1  C2
>   0   0.48
>   1   0.24
>   2   0.16
>   3   0.12
>
>    Now, I'm supposed to create 50 random values using this table. In
> MiniTab, I simply selected Calc -> Random Data -> Discrete, and selected
> the columns, and it created 50 random values in a new column.[1]
>
> How do I do the same thing in R?
>
>    [1] You may be wondering why I'm telling you this. Well, it's because
> if I were in your shoes, I'd think "Oh, someone wants me to solve his
> homework.". I have already solved it using MiniTab, but I want to be
> able to use R instead (since I prefer NetBSD).

You want to use the sample() function.  See ?sample.

Duncan Murdoch

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Re: New user: Custom probability distribution

Kjetil Halvorsen
In reply to this post by Jan Danielsson
Jan Danielsson wrote:

> Hello,
>
>    Given a probability function: p(x) = 12 / (25(x+1)) , x=0, 1, 2, 3 we
> generate the following values:
>
>   C1  C2
>   0   0.48
>   1   0.24
>   2   0.16
>   3   0.12
>
>    Now, I'm supposed to create 50 random values using this table. In
> MiniTab, I simply selected Calc -> Random Data -> Discrete, and selected
> the columns, and it created 50 random values in a new column.[1]
>
> How do I do the same thing in R?

sample( 0:3, 50, prob=c(0.48, 0.24, 0.26, 0.12))

Kjetil

>
>    [1] You may be wondering why I'm telling you this. Well, it's because
> if I were in your shoes, I'd think "Oh, someone wants me to solve his
> homework.". I have already solved it using MiniTab, but I want to be
> able to use R instead (since I prefer NetBSD).
>
>
>
> ------------------------------------------------------------------------
>
> ______________________________________________
> [hidden email] mailing list
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html

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Re: New user: Custom probability distribution

Prof. Dr. Matthias Kohl
In reply to this post by Jan Danielsson
Hi,

you can use our package distr respectively distrEx.
require(distrEx)
D1 <- DiscreteDistribution(supp=0:3, prob = 12/(25*(1:4)))
plot(D1)
r(D1)(50)

hth
Matthias

>Hello,
>
>   Given a probability function: p(x) = 12 / (25(x+1)) , x=0, 1, 2, 3 we
>generate the following values:
>
>  C1  C2
>  0   0.48
>  1   0.24
>  2   0.16
>  3   0.12
>
>   Now, I'm supposed to create 50 random values using this table. In
>MiniTab, I simply selected Calc -> Random Data -> Discrete, and selected
>the columns, and it created 50 random values in a new column.[1]
>
>How do I do the same thing in R?
>
>   [1] You may be wondering why I'm telling you this. Well, it's because
>if I were in your shoes, I'd think "Oh, someone wants me to solve his
>homework.". I have already solved it using MiniTab, but I want to be
>able to use R instead (since I prefer NetBSD).
>
>  
>
>------------------------------------------------------------------------
>
>______________________________________________
>[hidden email] mailing list
>https://stat.ethz.ch/mailman/listinfo/r-help
>PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html
>


--
StaMatS - Statistik + Mathematik Service
Dr. rer. nat. Matthias Kohl
Gottlieb-Keim-Stra├če 60
95448 Bayreuth
Phone: +49 921 50736457
E-Mail: [hidden email]
Home: www.stamats.de

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