[SciPy-user] optimize.fsolve starting guess

Askey Scott A Capt AFIT/ENY Scott.Askey@afit....
Wed Jan 14 11:34:14 CST 2009



-----Original Message-----
From: Askey Scott A Capt AFIT/ENY 
Sent: Wednesday, January 14, 2009 12:25 PM
To: 'scipy-user@scipy.org'
Subject: optimize.fsolve starting guess



-----Original Message-----
From: Askey Scott A Capt AFIT/ENY 
Sent: Wednesday, January 14, 2009 9:46 AM
To: scipy-user@scipy.org
Subject: optimize.fsolve starting guess

I am using fsolve to solve a systems of nonlinear equations to solve a
dynamics problem that is marching forward in time.

 

X(i+1)=fsolve(F,x(i),args=(x(i))

 

F is a vector.  My problem is Fsolve fail to converge as written above.
F(x[i],x[i]) contains many zeros.

 

It does converge if 

 

X(i+1)=fsolve(F,.99999*x(i),args=(x(i)) is used.

 

Is there a clever way to avoid the .99999 peturb the intial guess in a
computationally efficient manner?

Array(x, dtype= float32), x.round(6) ?

 

Thanks 

 

Scott



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