Re: Value of a random variable X at Time t

[Doug Stewart]

On Sat, Jun 12, 2021 at 2:36 AM umairjamali <umairahmedjamali@gmail.com> wrote:

BGreen wrote
> On Fri, Jun 11, 2021 at 3:52 PM umairjamali &lt;

> umairahmedjamali@

> &gt;
> wrote:
>
>> I defined a vector P that contains my probability distribution for a Dice
>> Roll, i.e. 6 equal probabilities for each outcome.
>>
>> Now, I want to define a variable T5 such that P[T5=t] = P{Xt is the first
>> random variable with outcome 5}
>> In other words: I start my process of tossing a die and T5 is the first
>> time
>> a 5 is diced.
>>
>> How would I define it with an _expression_?
>>
>> --
>> Sent from:
>> https://octave.1599824.n4.nabble.com/Octave-General-f1599825.html
>>
>
> You can use the rand function
> &lt;https://octave.sourceforge.io/octave/function/rand.html&gt; to
> generate
> random numbers, and then scale or round them to be uniform 1 through 6.
> P = floor(6*rand(1,N)+1)
> Then use find
> &lt;https://octav" mean(29): out of bound 1 (dimensions are 1x1) (note: variable 'mean'

shadows

 function)"e.sourceforge.io/octave/function/find.html&gt; to
> get the indices of all entries equal to 5:
> T = find(P==5)
> The first time a 5 is rolled is just the first element of T, i.e. it is
> T(1)..

Thank you. The find function worked and gave me and output of all times at
which T==5. Now , I want to calculate the mean of those times but when I
type mean(T) , it gives error:

" mean(29): out of bound 1 (dimensions are 1x1) (note: variable 'mean'
shadows
 function)"

Did you notice what the Note says?

You have made a new variable named "mean". So now Octave tries to use your new variable when you ask for the "mean" of a vector.

Rename your local var. to mean2 or some other name.

Use the clear function to remove all  old var names.

 

The output that I got from T=find(P==5) was something like this :
T =

   10   11   13   14   15   29

Is it a matrix or vector? In any case, how do I calculate the mean of this
output?




--
Sent from: https://octave.1599824.n4.nabble.com/Octave-General-f1599825.html

--

DAS