Skip to contents

Estimate first or second derivatives for dy/dx.

deriv.Rd

Uses central differencing where possible.

Usage

deriv(x, y, ord = 1, method = "direct", ends = "forwardback")

Arguments

x

x variable. Does not need to be evenly spaced.

y

y variable.

ord

Order of the derivative (1 or 2).

method

Method for taking second derivatives. Either

  • 'direct' (default) Uses a direct formula, based on a central difference of forward and backward differences, from https://mathformeremortals.wordpress.com/2013/01/12/a-numerical-second-derivative-from-three-points/

  • 'repeat' Repeat two first derivatives.

Value

Derivative of y relative to x.