Calculates the derivative of XY data.
An input XY series.
Optional. A series, the explicit X values.
An XY series.
W1: xy(gexp(100,.01), gline(100,.01, 1, 0))
W2 contains the first derivative of the XY data in W1.
W3: dydx(gline(100, .01, 1, 0), gexp(100, .01))
Same as above except the Y and X series are explicit.
W1: gsin(100, 1/100, 1);
W2 contains the first derivative of the interval data in W1. W2 is identical to W1 except for the last point.
DYDX computes the 2 point right derivative of an XY or interval series. The 2 point right derivative for a series s is defined as:
DYDX is identical to the built-in RDERIV function except for the last point. For a series of N points, the last point is computed as:
and for RDERIV:
See DERIV for a more sophisticated algorithm.
See DIFF to compute the series difference.