[WP 34s] Trapezoidal approximation of area under curve

[Dave Britten]

(06-01-2015 03:54 PM)Marcus von Cube Wrote:  

(06-01-2015 01:53 PM)Marcio Wrote:  Is it possible to have access to data keyed into the calc using the \(\sum +\) for other procedures other than stat functions?

The SUMS catalog has all the accumulated data ready for access. All commands in this catalog are programmable.

The problem is that the trapezoidal approximation appears to require the individual data points, and not just the sums. You'll probably have to write a custom program that accumulates its own sums, either on the fly, or by using a block of registers to store x and y data points.