PARTSUM

Purpose:

Calculates the partial sum of a series.

Syntax:

PARTSUM(series)

series

A series or table.

Returns:

A series or table.

Example:

partsum({20, 15, 30, 10, 25})

returns a series containing the cumulative sums {20, 35, 65, 75, 100}.

Remarks:

The n^th value of the output series is equal to the sum of the first n points of the input series:

$image\cumsum01.gif$

or by the equivalent difference equation:

$image\cumsum02.gif$

PARTSUM calculates the cumulative sum of a series. PARTSUM differs from integration in that the DELTAX information is not incorporated into the calculation.