Calculates the derivative of a series.
DERIV(series)
series |
- |
An interval or XY series, the series to differentiate. |
A series or table.
W1: {1, 3, 2, 7}
W2: deriv(w1)
W2 contains the derivative with values {2, 0.5, 2, 5} representing the slope of W1 at each point.
W1: gsin(1000,.001)
W2: xy(xvals(w1), yvals(w1))
W3: deriv(w1)
W4: deriv(w2)
W5: w3 - w4
W1 contains a 1 Hertz sinewave over one period as an interval series. W2 converts W1 into an XY series. The X values of W1 are implicit and can be constructed from the delta X value. The X values of W2 are explicit.
The derivatives of each series are calculated and the differences are displayed in W5.
DERIV calculates the derivative of evenly spaced (interval series) or unevenly spaced (XY series) data by taking the points at n-1, n, and n+1, finding the quadratic curve to fit those three points and returns the slope of the curve at point n as the derivative of the series at point n.
See LDERIV and RDERIV for 2 point derivative methods.
See FDERIV for an implementation in the frequency domain.
See DIFF to compute the series difference.