Gaussian integration for the HP-11C/15C

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(11-30-2016 03:18 PM)Marcio Wrote:  Does anyone know how to port this program ... to the 15C ... I can not figure out why it won't work on the 15c.

Did you retrieve this listing from this source ...
Archive 16
Numerical integration on the 11C
Message #4 Posted by Valentin Albillo on 17 June 2006, 11:57 p.m.,
in response to message #1 by Gerson W. Barbosa
...
as this POST includes the operating instructions?
There is a reference to the usage of the I Register

Code:

To use it to compute the integral of an arbitrary f(x) between x=a and x=b, using N-subinterval Gaussian integration, just do the following:
1.    Enter your f(x) to be integrated into program memory, starting at
2.             47 LBL E
ending it either with a RTN instruction or with the end of program memory.
3.    Store N, the number of subintervals you want to use, in Register I. N must be an integer number equal or greater than 1. The larger N, the more precise the result will be and the longer it will take to run.
4.             N,  STO I
5.    Enter the limits of integration, a and b, into the stack and call the integration routine:
6.             a, ENTER, b, GSB A
The computation will proceed and the result will be displayed upon termination. Let's see a couple of examples:

Hope this helps.

Best!
SlideRule