HP 42S, DM 42 Integral

[J-F Garnier]

(02-14-2021 03:27 AM)Thomas Okken Wrote:  The INTEG algorithm in Free42 is similar to that used in the HP-42S, i.e. Romberg integration with non-uniform spacing of sample points, and very similar performance in terms of convergence and accuracy. The one significant difference is that the HP-42S INTEG algorithm is smarter about when to stop the iteration...

The Romberg algorithm, as implemented in HP calculators starting with the 34C has no problem with null integrals by design, there are no special cases.
In HP implementation, the termination condition is based on the sum of the absolute values of the samples. Is it the same in Free42?

We discussed the HP algorithm last year, see here for some indications on the terminating condition.

J-F