Solved

Posted on 2003-03-10
Medium Priority
567 Views
Hello,

The problem that I have is that I am trying to add Poisson distributed noise to a set of data, which is simply stored as a list of numbers. I was wondering if anyone knew any easy ways of performing this task.

Many thanks

0
Question by:FaustVs
[X]
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

• Help others & share knowledge
• Earn cash & points
• 3
• 2

Expert Comment

ID: 8104116
Can you explain more what you want? I don't understand your question, what is Poison Nose?
0

LVL 5

Accepted Solution

msa2003 earned 200 total points
ID: 8104495
Poisson distribution looks like:

P(X = m) = (a^m)*exp(-a)/(m!)
where a=M(X)

First, choose a range of X Poisson-distributed values. Because X allwais is a integer number, the range will contain a number of possible values. For example, if a=0.1 there is enough to calculate 5 values (X = 0 ... 4); if a=10, 30 values is enough. Probabilities of the other values will be very small (less then 0.000001). Build the table of (X, Y) values using the following rules.

P(0) = exp(-a);
P(X + 1) = P(X) * a / (X + 1);
Y(0) = P(0);
Y(X + 1) = Y(X) + P(X + 1)

Now suppose that we have random generator with uniform distribution (for example, pascal's Random function) which will generate continuous values from 0 to 1 exclusively. Call it R. Generate R = 0 ... 1 and using binary or straight search find the nearest Y(X) value. X will be the poisson-distributed value.

This method is called "table method" and could be used to generate a number X values with constant a (Poisson distributed noise).
0

LVL 5

Expert Comment

ID: 8104510
tilex: learn math ;)
0

Expert Comment

ID: 8104576
I'm only in secondary 3...I don't konw what's its like in US but well I'm 15, IV'E got math notions but I'm not that far...
0

LVL 5

Expert Comment

ID: 8105925
tilex: I hope you would like it ;)
0

Featured Post

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Although it can be difficult to imagine, someday your child will have a career of his or her own. He or she will likely start a family, buy a home and start having their own children. So, while being a kid is still extremely important, it’s also …
Q&A with Course Creator, Mark Lassoff, on the importance of HTML5 in the career of a modern-day developer.
In this fifth video of the Xpdf series, we discuss and demonstrate the PDFdetach utility, which is able to list and, more importantly, extract attachments that are embedded in PDF files. It does this via a command line interface, making it suitable …
Progress
Suggested Courses
Course of the Month11 days, 18 hours left to enroll