42S statistics registers

[Dave Britten]

(11-20-2019 04:39 PM)Werner Wrote:  Nice program, Dave.
I do not understand the use of flags 61,62 and 63, however.
I would think flag 60 is all you need: if it is set, all 13 statistics registers are used, whatever the fitting model is that is chosen.

And I would’ve written

Code:

Rv
RCL IND ST T

instead of

Code:

SF 30
RCL IND ST X

Cheers, Werner

Flags 61, 62, and 63 indicate which of the different models/sums are invalid based on the data you've entered. If you supply a zero for any of the X or Y values, then the sums that take the logarithm of those values are no longer valid. These flags are checked to prevent returning that invalid/incorrect data.