# Need help to plot equation

Asked by Idriss on 9 Aug 2012
Latest activity Commented on by Matt Fig on 10 Aug 2012

Hello, can someone help me to plot this equation?

T_b^*=\sum_{i=0}^n r_i \pi_i = \sum_{i=1}^{n} p_b(i) \pi_i + \pi_0


with:

p_b(i)= \frac{ (\lambda/\mu)^i / i!)}{\sum_{j=0}^i (\lambda/ \mu)^j / j! }


and

\pi_0=[\sum_{i=0}^n \frac{1}{i!}(\tau/\gamma)^i]^{-1}\; \hspace{1.5cm} \pi_i= ((\tau/\gamma)^i / i!)\pi_0\;


Idr

## 1 Comment

Wayne King on 9 Aug 2012

You don't tell us the value of \tau, or the value of \gamma, or the value of \lambda or \mu. We can just plug values in for those, but the major issue is what is n in your first sum, is n an index that varies so that you get something like a cumulative sum? (a vector). Otherwise, you just have a scalar, T_b^* is just a number. And what do you want to plot, what as a function of what?

## Products

No products are associated with this question.

Answer by Idriss on 10 Aug 2012
Edited by Walter Roberson on 10 Aug 2012

Thank for your comment Wayne, following the parameters : \tau=1/24, \gamma=1\1000, \lambda=49 and \mu=0.5

But in Matlab documentation, It seems that it possible to use the symbolic summation and then convert to double to plot the Tb. For exemple:

Tb1=symsum(ro^i*ro2^i/(sym('i!')*sym('i!')*symsum(ro2^j/sym('j!'),j,0,sym('i'))*symsum(ro^i/sym('i!'),i,0,10)),i,0,10);