Francesc Alted wrote:
Hi,
I'm trying to figure out how to compute the derivatives of a function with scipy, but the documentation is a bit terse for me:
def derivative(func,x0,dx=1.0,n=1,args=(),order=3): """Given a function, use an N-point central differenece formula with spacing dx to compute the nth derivative at x0, where N is the value of order and must be odd.
Warning: Decreasing the step size too small can result in round-off error. """
I would like to compute a derivative of an arbitrary order, but by reading the docs, I'm not sure what the n and order parameters exactly means.
Someone smarter than me can help me?
'n' as in d^n/dx^n . Somewhat confusingly, 'N' is being used in the docstring as a synonym for 'order' and is the number of discrete points used to evaluate the numerical derivative. I'm going to fix that. For example, when n=2, and order=3, one is computing the second central derivative using 3 points [x0-dx, x0, x0+dx]. -- Robert Kern rkern@ucsd.edu "In the fields of hell where the grass grows high Are the graves of dreams allowed to die." -- Richard Harter