2007-08-22  Brian Gough  <bjg@network-theory.co.uk>

	* deriv.c (central_deriv): corrected dy term for error in h
	(forward_deriv): corrected dy term for error in h

2004-03-06  Brian Gough  <bjg@network-theory.co.uk>

	* reworking API of gsl_diff

