(34S) Integration (using the double-exponential method)

[Dieter]

(03-26-2017 06:34 PM)emece67 Wrote:  Surely that's the behavior of the 34C, but the 34s:

1. Returns the computed result in X
2. Returns in Y what seems to be some kind of a previous approximation to the result (it is not much smaller than the result, as expected for an error estimation, but approximately equal to it)
3. Returns the integration limits in Z & T
4. Returns the upper integration limit in L
   

AFAIR one of the final steps of the integration routine was a STO–Y so that Y does not hold the previous approximation but the difference compared to the last one. The content of the other lower stack registers are just as they are supposed to.

(03-26-2017 06:34 PM)emece67 Wrote:  5. Corrupts ABCD with some unknown data (no matter if the user is in SSIZE4 or SSIZE8, ABCD are always corrupted)

A, B, C and D may be corrupted, yes.

(03-26-2017 06:34 PM)emece67 Wrote:  Thus, I've modified my program to behave more or less in the same way, so it now (v1.1r and v1.1x):

1. Returns the computed result in X (as before)
2. Returns in Y the previous approximation to the result
3. Returns the integration limits in Z & T
4. Returns the upper integration limit in L (as before)
5. Keeps ABCD untouched (no matter if the user is in SSIZE4 or SSIZE8)
   

I would prefer an error estimate in Y, as it is returned by the 34C and 15C. And I think this also is the way the 34s integration routine is supposed to work. Pauli?

Dieter