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Stats 2Var question
05-02-2017, 02:13 PM
Post: #1
Stats 2Var question
Hello

In Stats 2Var spreadsheet, following formula entered at the bottom of column C2
PredY(50): correct, numerical result as expected
=PredY(50): syntax error. Why? No need to have the value updated with the stats data?

tested in both Algebraic and Book modes.

Help much appreciated!
Many thanks advanced and kind regards.
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05-03-2017, 07:26 PM
Post: #2
RE: Stats 2Var question
Is my question that dumb?
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05-03-2017, 07:36 PM (This post was last modified: 05-03-2017 07:41 PM by Tim Wessman.)
Post: #3
RE: Stats 2Var question
I didn't see your question before.

The stat editor is not a spreadsheet. It is a list editor for data. Having live updating columns creates ALL sorts of problems as you can very easily create recursive data (which you actually just did by doing this attempt).

You have a data column of C1/C2 in your symb defining your fit. PredY attempts to evaluates your fit, which evaluates your data that contains PredY, so it then attempts to evaluate your fit which evaluates your data that contains PredY, which then attempts evaluate your fit which evaluates your data that contains PredY, which then attempts to evaluate your fit which evaluates your data that contains PredY.... Smile

No, there generally is NOT need to have live updating *data* in your stat columns. Your data is fixed. It does not change. Modifying the *data* is a really bad thing to be doing when looking at statistics in general.

You can define your DEFINITIONS in symb as those *are* formulas meant to be evaluated. The definitions there are not just C1, C2 and so on, but can be things like LOG(C1) or C1*C2+5 or even define S2 as C1, PredY(C1) or C1, Resid(S1).

TW

Although I work for the HP calculator group, the views and opinions I post here are my own.
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05-04-2017, 07:44 AM
Post: #4
RE: Stats 2Var question
Hello Tim

Thank you for your kind answer. No need to apologize for the very short delay.

I was mistaken by the visual aspect of the Stat 2Var window, which looks pretty much like the Spreadsheet. You explanation makes sense.
I was having several times the same need of using PredY after having entered new data in the C2 column and was wondering whether it could be faster to have it directly in the Stat app rather than having to exit the App to call PredY from the Home window.
Perhaps is there a way for improvement, by having a zone in the Stat App separated from data, dedicated to results?

Kind regards.
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