#POLYROOTS PYTHON FUCTION CODE#

X = random() # Starting value (random number)ĭef deflPoly(a,root): # Deflates a polynomial The roots are returned in the array 'roots', Uses Laguerre's method to compute all the roots ofĪ + a*x + a*x^2 +.+ a*x^n = 0.

#POLYROOTS PYTHON FUCTION CODE#

The polyRoots script is a book code resource from numerical methods to engineering. I get the following error: File 'C:temp.py', line 13, in ĪttributeError: 'function' object has no attribute 'deflPoly' Their is nothing complicated about this code and I am unsure why it isn't working. When I tried to utilize the deflating poly function I get an error. Real roots are placed first in the returned list, sorted by value.Tried creating a little script to test out the different parts of a script called polyRoots.

Root found to have an imaginary part smaller than the estimated numericalĮrror is truncated to a real number (small real parts are also chopped). The convergence to simple roots is quadratic, just like Newton’sĪlthough all roots are internally calculated using complex arithmetic, any Simultaneous Newton iteration for all the roots. The Durand-Kerner method can be viewed as approximately performing Uses complex arithmetic to locate all roots simultaneously. Polyroots() implements the Durand-Kerner method, which Typically compute all roots of an arbitrary polynomial to high precision: Provided there are no repeated roots, polyroots() can It is possible to getĬonvergence to a wrong answer with too low extraprec. The user should always do a convergence study with regards toĮxtraprec to ensure accurate results. NoConvergence was raised, that is caused either by not having enoughĮxtra precision to achieve convergence (in which case increasingĮxtraprec should fix the problem) or too low maxsteps (in whichĬase increasing maxsteps should fix the problem), or a combination of

The current working precision extended by extraprec. If thisĪccuracy cannot be achieved in maxsteps steps, then a The roots are computed to the current working precision accuracy.

Polyroots python fuction