# Exponential arrival distribution in Python

Discussion in 'Python' started by Ricky, Nov 28, 2012.

1. ### RickyGuest

Hi all,

I am doing a project on traffic simulation. I want to introduce exponentialarrival distribution to precede this task. Therefore I want write a code in python for exponential arrival distribution. I am very new for programming and if anybody can help me on this that would be great.

Cheers,
Ricky
Ricky, Nov 28, 2012

2. ### David HuttoGuest

>> I am doing a project on traffic simulation. I want to introduce
>> exponential arrival distribution to precede this task. Therefore I want
>> write a code in python for exponential arrival distribution. I am very new
>> for programming and if anybody can help me on this that would be great.

First, I would suggest that you give yourself a GUI like tkinter,
wxpython to visualize the data. An average of the sequential(averaged
per 60 second intervals) traveled by drivers on the road, and at what
times.

Then, and I don't know why, but it seems you want a logarithmic, scale where:

for i in range(0,4)
print "%i = %i" % (i * 10 **i)

--
Best Regards,
David Hutto
CEO: http://www.hitwebdevelopment.com
David Hutto, Nov 28, 2012

3. ### David HuttoGuest

David Hutto, Nov 28, 2012
4. ### Paul RubinGuest

Ricky <> writes:
> I am doing a project on traffic simulation. I want to introduce
> exponential arrival distribution to precede this task. Therefore I
> want write a code in python for exponential arrival distribution.

I've never heard of an "exponential arrival distribution" and googling
fails. Do you mean an exponential distribution, that describes the
expected arrival times in a Poisson process? Python's "random" module
has the random.expovariate function for that:

http://docs.python.org/3/library/random.html

If you want an actual (discrete) Poisson distribution, see:

http://en.wikipedia.org/wiki/Poisson_distribution#Generating_Poisson-distributed_random_variables
Paul Rubin, Nov 28, 2012
5. ### Albert Chun-Chieh HuangGuest

Hi, Ricky,

Traffic simulation sounds like a good topic to use SimPy, which is a
discrete-event simulation library in Python,
c.f. http://simpy.sourceforge.net

Professor Norm Matloff wrote a very good tutorial on SimPy, and you can
Also, I've presented this SimPy package before, my slides might be
http://alberthuang314.blogspot.tw/2012/01/simpy-slides-in-our-company-and-pyhug_26.html

In short, SimPy is a process-oriented discrete-event simulation package,
which will be easier to maintain than event-oriented discrete-event
simulation. It also contains some tools to help us to visualize
simulation data. It takes some time to study it, but if you would like to do
some simulation projects, it will definitely be a good investment! Have
fun with simulation!

with Regards,

Albert Huang

Ricky <> writes:

> Hi all,
>
> I am doing a project on traffic simulation. I want to introduce exponential arrival distribution to precede this task. Therefore I want write a code in python for exponential arrival distribution. I am very new for programming and if anybody can help me on this that would be great.
>
> Cheers,
> Ricky
Albert Chun-Chieh Huang, Nov 28, 2012
6. ### duncan smithGuest

On 28/11/12 21:34, Ricky wrote:
>
> Hi all,
>
> I am doing a project on traffic simulation. I want to introduce exponential arrival distribution to precede this task. Therefore I want write a code in python for exponential arrival distribution. I am very new for programming and if anybody can help me on this that would be great.
>
> Cheers,
> Ricky
>

Maybe you mean something like,

>>> from random import expovariate
>>> expovariate(1)

0.09133428954823608
>>> expovariate(1)

2.5388809393383407
>>>

Duncan
duncan smith, Nov 29, 2012