num.deriv: Numerical derivative by Ridders' method.

In sandroklippel/fishassess: Functions on fishery biology, stock assessment and management.

Description

Evaluates numerically the derivative of a function at a point by Ridders' method.

Usage

num.deriv(fun, x, h=0.5, ...)

Arguments

fun	function
x	location of function
h	initial stepsize
...	further parameters to function

Value

List with components

deriv	the derivative value.
error	estimate of the error.

Author(s)

Sandro Klippel

References

Press, W., Teukolsky, S., Vetterling, W., Flannery, B., 1992. Numerical Recipes in FORTRAN 77: The Art of Scientific Computing, 2nd Edition. Cambridge University Press, Cambridge.

See Also

F0.1

Examples

# F(x)  = x^3 / 3 - x
# F'(x) = x^2 - 1 
num.deriv(fun=function(x){x^3/3-x},-1)
(-1^2)-1

# F(x)  = sin(x)
# F'(x) = cos(x)
num.deriv(sin, 4)
cos(4)

sandroklippel/fishassess documentation built on June 5, 2019, 10:54 a.m.