Matlab help on Financial Estimation!!?

[deaconblues]

Hi, I am trying to use matlab for my financial estimation paper. I am using matlab to find out the probability of default using a DOC model. I am facing issues big time, since it's been almost 3 years since I last used matlab
1. Maximum likelihood estimation:
I am using the equation
ve = va* N(d1)- exp(-rT)*X*N(d2)
where d1 = (log(Va/X)+ (r+(sigma^2/2))*T)/ (sigma*sqrt(T))
and d2 = d1 - (sigma *sqrt(T))
I have the values of ve, X, r and T. I need to find out v, sigma and alpha (a barrier level - a part of a bigger equation) using Maximum Likelihood Estimation (iteratively).
I am trying to use GARCHFIT and MLE functions but they're throwing up errors. I am not able to figure out ow to input arguments to these functions and can't understand what outputs I get
Can somebody please help me on this?
cheers
dB

[shwaip]

can you post the entirety of your code (along with the known values)?

put it inside tags, please.

[deaconblues]

can you post the entirety of your code (along with the known values)?

put it inside tags, please.

Hi sorry for the late reply. Have been breaking my head over this matlab code.

I will rephrase my request....

I have the following function:

L(sigma,alpha,Ve)= f(Ve,r,T,X,alpha,sigma,Ve,mu)

The entire function is here: http://picasaweb.google.co.uk/satishtn/MatlabHelp (http://picasaweb.google.co.uk/satishtn/MatlabHelp)

I need to get the maximum value of sigma, alpha and Ve for
the inputted values of other variables. I am thinking of
using Nelder-Mead model as per the following matlab code:
http://www4.ncsu.edu/~ctk/darts/nelder.m (http://www4.ncsu.edu/~ctk/darts/nelder.m)

Since I am a beginner, I find this too complex. I
understand I need to model my function above in the Melder-
mead model and voila! I should get the required values
after iteration. But, I just dont know how to do it.

I would be grateful for any guidance/ alternative
suggestions. I need to get the data set done for my
dissertation in finance.

Thanks in advance

cheers
dB