Package gmisclib :: Module root

Module root

Solve a 1-dimensional equation to find the roots. This does alternating secant and bisection steps. It will work for any function, discontinuous or not. For a nasty function, it might be a factor of 2 slower than bisection, but for a nearly-linear function, it can be much faster than bisection.

Functions

float

root(f, xl, xh, p, epsx, epsf)
Find a root of an equation.

source code

test()

source code

iroot(y, xl, xh, epsy=0.0)
Find a zero in an array y.

source code

testi()

source code

Variables
	__package__ = `None` hash(x)

Function Details

root(f, xl, xh, p, epsx, epsf)

source code

Find a root of an equation.

Parameters:

f - is the function to solve, called as f(x, p).
p - is arbitrary data for f. This function assumes there is known to be a root in [xl,xh] and that f(xl,p) has a different sign from f(xh,p). It finds it within a region of width epsx, or at least finds an x such that -epsf < f(x, p) < epsf .

Returns: float

a root in the interval

iroot(y, xl, xh, epsy=0.0)

source code

Find a zero in an array y. This function assumes there is known to be a root in [xl,xh]. It returns a real-number index into the array which linearly interpolates to zero.