HP50G and built-in variable sigmaDAT

[Gil]

If I want to calculate the built-in CORR function between two variables, the first one situated in the first column and the second one in the second column of the special sigmaDAT variable (in the HP50G),
I cannot use the (apparently logical) exact mode
(1 2 0. 0. LINFIT )
'SigmaDAT' STO
in order to execute afterwards
the built-in command-function CORR.

Instead, I do have to use the approximate mode
{1. 1. 0. 0. LINFIT } (dots inside the {}).
'SigmaDAT' STO
and then execute
the built-in command-function CORR.

Why this (seemingly illogical?) restriction?

I thank you for your clues relative to that matter.

Regards,
Gil

[Dave Britten]

Isn't that SigmaPAR rather than SigmaDAT? SigmaDAT would be the matrix with your data in it.

Anyway, I'm assuming they simply didn't update the stat operations to handle ints, since you mostly manipulate SigmaPAR with various menus, and modifying SigmaPAR yourself is left for advanced users/programmers that should know better. The commands probably just check for real list elements and bail when they see a type mismatch.