Question

this is the code i have written for ps2 http://pastebin.com/GawtDFrL there is a error in the last part i.e to calculate the root of the polynomial.please could you let me know my mistake.
(about newton's method)

Answer 1

I found a few bugs.

http://pastebin.com/U8KcLmuQ
has the corrections

Line 4 should be
valpoly = valpoly + (poly[i]*x**i)
instead of valpoly = sumpoly + (poly[i]*x**i)

also, you need to have your functions return values
so add
return valpoly
as line 5 of your evaluate_poly function
and
return deriv
should be added at the end of compute_deriv

lastly, you need to add some harness code to run the functions.

polyMy = (-13.39, 0.0, 17.5, 3.0, 1.0)
print compute_root(polyMy, .01, .0001)

Answer 2

thanks a lot...was the main mistake that i didn`t return the value in the function?

Answer 3

yes, both evaluate_poly and compute_deriv needed to return a value